3d sonar systems and methods

ABSTRACT

Techniques are disclosed for systems and methods to provide accurate and compact three dimensional (3D) capable multichannel sonar systems for mobile structures. A 3D capable multichannel sonar system includes a multichannel transducer and associated processing and control electronics and optionally orientation and/or position sensors disposed substantially within the housing of a sonar transducer assembly. The multichannel transducer includes multiple transmission and/or receive channels/transducer elements. The transducer assembly is configured to support and protect the multichannel transducer and associated electronics and sensors, to physically and/or adjustably couple to a mobile structure, and/or to provide a simplified interface to other systems coupled to the mobile structure. Resulting sonar data and/or imagery may be displayed to a user and/or used to adjust a steering actuator, a propulsion system thrust, and/or other operational systems of the mobile structure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/US2019/062871 filed Nov. 22, 2019 and entitled “3D SONAR SYSTEMS ANDMETHODS” which claims the benefit of and priority to U.S. ProvisionalPatent Application No. 62/771,547 filed Nov. 26, 2018 and entitled “3DSONAR SYSTEMS AND METHODS” which are hereby incorporated by reference intheir entirety.

This application is a continuation-in-part to U.S. patent applicationSer. No. 15/893,431 filed Feb. 9, 2018 and entitled “3D BOTTOM SURFACERENDERING SYSTEMS AND METHODS,” which claims priority to and the benefitof U.S. Provisional Patent Application No. 62/458,529 filed Feb. 13,2017 and entitled “3D BOTTOM SURFACE RENDERING SYSTEMS AND METHODS,”both of which are incorporated herein by reference in their entirety.

This application is related to U.S. patent application Ser. No.15/893,465 filed Feb. 9, 2018 and entitled “3D SCENE ANNOTATION ANDENHANCEMENT SYSTEMS AND METHODS,” which claims priority to and thebenefit of U.S. Provisional Patent Application No. 62/458,533 filed Feb.13, 2017 and entitled “3D SCENE ANNOTATION AND ENHANCEMENT SYSTEMS ANDMETHODS,” both of which are incorporated herein by reference in theirentirety.

This application is related to U.S. patent application Ser. No.15/494,232 filed Apr. 21, 2017 and entitled “PILOT DISPLAY SYSTEMS ANDMETHODS,” which is a continuation of International Patent ApplicationNo. PCT/US2015/056786 filed Oct. 21, 2015 and entitled “PILOT DISPLAYSYSTEMS AND METHODS”, both of which are hereby incorporated by referencein their entirety. International Patent Application No.PCT/US2015/056786 claims priority to and the benefit of U.S. ProvisionalPatent Application No. 62/066,802 filed Oct. 21, 2014 and entitled“ENHANCED SONAR DISPLAY USING CW/FM PULSE OVERLAYS” and U.S. ProvisionalPatent Application No. 62/069,961 filed Oct. 29, 2014 and entitled“PILOT DISPLAY SYSTEMS AND METHODS”, both of which are herebyincorporated by reference in their entirety.

This application is related to U.S. patent application Ser. No.15/353,579 filed Nov. 16, 2016 and entitled “MULTICHANNEL SONAR SYSTEMSAND METHODS,” which is a continuation of International PatentApplication No. PCT/US2015/032304 filed May 22, 2015 and entitled“MULTICHANNEL SONAR SYSTEMS AND METHODS,” which claims priority to andthe benefit of U.S. Provisional Patent Application No. 62/005,838 filedMay 30, 2014 and entitled “MULTICHANNEL SONAR SYSTEMS AND METHODS,” allthree of which are hereby incorporated by reference in their entirety.

TECHNICAL FIELD

One or more embodiments of the invention relate generally to sonarsystems and more particularly, for example, to systems and methods forproviding sonar imagery, including three dimensional sonar imagery.

BACKGROUND

Sonar may be used to perform bathymetry, detect underwater hazards, findfish, and/or otherwise assist in navigation by producing data and/orimagery of a water column beneath a watercraft. Conventional sonarsystems often include one or more independently operating sonartransducers with temporally and/or spatially non-overlapping beamsarranged to help differentiate ensonifications and produce traditionallyrecognizable sonar imagery.

Higher quality sonar imagery has conventionally been associated withrelatively large and unwieldy sonar transducer assemblies that canpreclude operation in shallow depths. Sonar systems incorporating suchassemblies are typically expensive and cannot be used with a largeportion of non-commercial watercraft. At the same time, consumer marketpressures and convenience dictate smaller and easier to use systems thatinclude more features and produce higher quality resulting imagery.Thus, there is a need for an improved methodology to provide compact yetfeature-rich and flexible-use sonar systems, particularly in the contextof providing relatively high quality enhanced sonar data and/or imagery.

SUMMARY

Techniques are disclosed for systems and methods to provide accurate andcompact three dimensional (3D) capable and/or multichannel sonar systemsfor mobile structures. A 3D capable sonar system may include amultichannel transducer and associated processing and controlelectronics and optionally orientation and/or position sensors disposedsubstantially within the housing of a sonar transducer assembly. Themultichannel transducer may include multiple transmission and/or receivechannels/transducer elements. The transducer assembly may be configuredto support and protect the multichannel transducer and associatedelectronics and sensors, to physically and/or adjustably couple to amobile structure, and/or to provide a simplified interface to othersystems coupled to the mobile structure. The system may additionallyinclude an actuator configured to adjust an orientation of thetransducer assembly. Resulting sonar data and/or imagery may bedisplayed to a user and/or used to adjust various operational systems ofthe mobile structure.

In various embodiments, a 3D capable sonar system may include anorientation sensor, a position sensor, a gyroscope, an accelerometer,and/or one or more additional sensors, actuators, controllers, userinterfaces, mapping systems, and/or other modules mounted to or inproximity to a vehicle. Each component of the system may be implementedwith a logic device adapted to form one or more wired and/or wirelesscommunication links for transmitting and/or receiving sensor signals,control signals, or other signals and/or data between the variouscomponents.

In one embodiment, a system may include a sonar transducer assemblyincluding a housing adapted to be mounted to a mobile structure; amultichannel transducer disposed within the housing; and a logic devicedisposed within the housing and in communication with the multichanneltransducer. The logic device may be configured to receive a series ofacoustic returns from the multichannel transducer; generate a set ofspatial sonar data based, at least in part, on the series of acousticreturns; and generate an enhanced three dimensional (3D) and/or sidescanrepresentation of an underwater environment associated with the mobilestructure based, at least in part, on a set of spatial data differentfrom the set of spatial sonar data.

In another embodiment, a method may include receiving a series ofacoustic returns from a multichannel transducer disposed within ahousing of a sonar transducer assembly adapted to be mounted to a mobilestructure; generating a set of spatial sonar data based, at least inpart, on the series of acoustic returns; and generating an enhancedthree dimensional and/or sidescan representation of an underwaterenvironment associated with the mobile structure based, at least inpart, on a set of spatial data different from the set of spatial sonardata.

The scope of the invention is defined by the claims, which areincorporated into this section by reference. A more completeunderstanding of embodiments of the invention will be afforded to thoseskilled in the art, as well as a realization of additional advantagesthereof, by a consideration of the following detailed description of oneor more embodiments. Reference will be made to the appended sheets ofdrawings that will first be described briefly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A illustrates a block diagram of a multichannel sonar system inaccordance with an embodiment of the disclosure.

FIG. 1B illustrates a diagram of a multichannel sonar system inaccordance with an embodiment of the disclosure.

FIG. 2A illustrates a diagram of a multichannel sonar system inaccordance with an embodiment of the disclosure.

FIG. 2B illustrates a diagram of a sonar transmitter in accordance withan embodiment of the disclosure.

FIG. 2C illustrates various signals of a sonar transmitter in accordancewith an embodiment of the disclosure.

FIGS. 3A-B illustrate diagrams of multichannel sonar systems inaccordance with embodiments of the disclosure.

FIGS. 3C-D illustrate diagrams of various transducer configurations formultichannel sonar systems in accordance with embodiments of thedisclosure.

FIG. 3E illustrates various sonar beams produced by multichannel sonarsystems in accordance with embodiments of the disclosure.

FIG. 4A illustrates a diagram of a cross section of a multichannel sonarsystem in accordance with an embodiment of the disclosure.

FIGS. 4B-C illustrate diagrams of sonar transducers and correspondingbeams for use in a multichannel sonar system in accordance withembodiments of the disclosure.

FIGS. 5-7 illustrate various display views of sonar data provided by amultichannel sonar system in accordance with embodiments of thedisclosure.

FIGS. 8-9 illustrate various configurations of multichannel sonarsystems in accordance with embodiments of the disclosure.

FIG. 10A illustrates a flow diagram of various operations to operate amultichannel sonar system in accordance with an embodiment of thedisclosure.

FIG. 10B illustrates a flow diagram of various operations to operate amultichannel sonar system in accordance with an embodiment of thedisclosure.

FIGS. 11A-B illustrate diagrams of various transducer configurations formultichannel sonar systems in accordance with embodiments of thedisclosure.

FIGS. 12A-B illustrate various display views of sonar data provided by amultichannel sonar system in accordance with embodiments of thedisclosure.

FIG. 13A-C illustrate various display views of sonar data provided by amultichannel sonar system in accordance with embodiments of thedisclosure.

FIG. 14 illustrates a flow diagram of various operations to operate amultichannel sonar system in accordance with an embodiment of thedisclosure.

Embodiments of the invention and their advantages are best understood byreferring to the detailed description that follows. It should beappreciated that like reference numerals are used to identify likeelements illustrated in one or more of the figures.

DETAILED DESCRIPTION

In accordance with various embodiments of the present disclosure,compact three dimensional capable multichannel sonar systems and methodsmay advantageously include a controller and one or more multichannelsonar transducer assemblies in conjunction with an orientation sensor, agyroscope, an accelerometer, a position sensor, and/or a speed sensorproviding measurements of an orientation, a position, an acceleration,and/or a speed of the multichannel sonar transducer assemblies and/or acoupled mobile structure. For example, the sensors may be mounted to orwithin the mobile structure (e.g., a watercraft, aircraft, motorvehicle, and/or other mobile structure), or may be integrated with themultichannel sonar transducer assemblies and/or the controller.

Embodiments of the present disclosure can reliably produce higherquality imagery and be easier to use than conventional systems and/ormethods through use of multiple sonar channels and various multichannelprocessing techniques, and/or by automatically coordinating multichannelsonar operation with various orientation and/or position measurements.Moreover, such embodiments may be relatively compact and may be formedaccording to a number of unique multichannel sonar transducerarrangements. The unique multichannel sonar transducer arrangements, inturn, provide various opportunities to develop new sonar processingand/or data accumulation techniques, as described herein.

FIG. 1A illustrates a block diagram of system 100 in accordance with anembodiment of the disclosure. In various embodiments, system 100 may beadapted to measure an orientation, a position, an acceleration, and aspeed of mobile structure 101 and/or sonar system 110 (e.g., amultichannel sonar system). System 100 may then use these measurementsto form various views of sonar data provided by sonar system 110 and/orto adjust an orientation of sonar system 110 according to a desiredoperation of sonar system 110 and/or mobile structure 101. In someembodiments, system 100 may display resulting sonar data and/or imageryto a user through user interface 120, and/or use the sonar data and/orimagery to control operation of mobile structure 101, such ascontrolling steering actuator 150 and/or propulsion system 170 to steermobile structure 101 according to a desired heading, such as headingangle 107, for example.

In the embodiment shown in FIG. 1A, system 100 may be implemented toprovide sonar data and/or imagery for a particular type of mobilestructure 101, such as a drone, a watercraft, an aircraft, a robot, avehicle, and/or other types of mobile structures. In one embodiment,system 100 may include one or more of a sonar system 110, a userinterface 120, a controller 130, an orientation sensor 140, a speedsensor 142, a gyroscope/accelerometer 144, a global navigation satellitesystem (GNSS) 146, a steering sensor/actuator 150, a propulsion system170, and one or more other sensors and/or actuators, such as othermodules 180. In some embodiments, one or more of the elements of system100 may be implemented in a combined housing or structure that can becoupled to mobile structure 101 and/or held or carried by a user ofmobile structure 101.

Directions 102, 103, and 104 describe one possible coordinate frame ofmobile structure 101 (e.g., for headings or orientations measured byorientation sensor 140 and/or angular velocities and accelerationsmeasured by gyroscope 144 and accelerometer 145). As shown in FIG. 1A,direction 102 illustrates a direction that may be substantially parallelto and/or aligned with a longitudinal axis of mobile structure 101,direction 103 illustrates a direction that may be substantially parallelto and/or aligned with a lateral axis of mobile structure 101, anddirection 104 illustrates a direction that may be substantially parallelto and/or aligned with a vertical axis of mobile structure 101, asdescribed herein. For example, a roll component of motion of mobilestructure 101 may correspond to rotations around direction 102, a pitchcomponent may correspond to rotations around direction 103, and a yawcomponent may correspond to rotations around direction 104.

Heading angle 107 may correspond to the angle between a projection of areference direction 106 (e.g., the local component of the Earth'smagnetic field) onto a horizontal plane (e.g., referenced to agravitationally defined “down” vector local to mobile structure 101) anda projection of direction 102 onto the same horizontal plane. In someembodiments, the projection of reference direction 106 onto a horizontalplane (e.g., referenced to a gravitationally defined “down” vector) maybe referred to as Magnetic North. In various embodiments, MagneticNorth, a “down” vector, and/or various other directions, positions,and/or fixed or relative reference frames may define an absolutecoordinate frame, for example, where directional measurements referencedto an absolute coordinate frame may be referred to as absolutedirectional measurements (e.g., an “absolute” orientation). In someembodiments, directional measurements may initially be referenced to acoordinate frame of a particular sensor (e.g., a sonar transducerassembly or module of sonar system 110) and be transformed (e.g., usingparameters for one or more coordinate frame transformations) to bereferenced to an absolute coordinate frame and/or a coordinate frame ofmobile structure 101. In various embodiments, an absolute coordinateframe may be defined and/or correspond to a coordinate frame with one ormore undefined axes, such as a horizontal plane local to mobilestructure 101 referenced to a local gravitational vector but with anunreferenced and/or undefined yaw reference (e.g., no reference toMagnetic North).

Sonar system 110 may be implemented as one or more electrically and/ormechanically coupled controllers, transmitters, receivers, transceivers,signal processing logic devices, various electrical components,transducer elements of various shapes and sizes, multichanneltransducers/transducer modules, transducer assemblies, assemblybrackets, transom brackets, and/or various actuators adapted to adjustorientations of any of the components of sonar system 110, as describedherein. Sonar system 110 may be configured to emit one, multiple, or aseries of acoustic beams, receive corresponding acoustic returns, andconvert the acoustic returns into sonar data and/or imagery, such asbathymetric data, water depth, water temperature, water column/volumedebris, bottom profile, and/or other types of sonar data. Sonar system110 may be configured to provide such data and/or imagery to userinterface 120 for display to a user, for example, or to controller 130for additional processing, as described herein.

In some embodiments, sonar system 110 may be implemented using a compactdesign, where multiple sonar transducers, sensors, and/or associatedprocessing devices are located within a single transducer assemblyhousing that is configured to interface with the rest of system 100through a single cable providing both power and communications to andfrom sonar system 110. In some embodiments, sonar system 110 may includeorientation and/or position sensors configured to help provide two orthree dimensional waypoints, increase sonar data and/or imagery quality,and/or provide highly accurate bathymetry data, as described herein.

For example, in the context of sea based sonar, fisherman desire highlydetailed and accurate information and/or imagery of underwater structureand mid water targets (e.g., fish). Conventional sonar systems arerelatively expensive and bulky and typically cannot be used to provideenhanced underwater views, as described herein. Embodiments of sonarsystem 110 provide a low cost multichannel sonar system that can beconfigured to produce detailed two and three dimensional sonar dataand/or imagery. In some embodiments, sonar system 110 may consolidateelectronics and transducers into a single waterproof package to reducesize and costs, for example, and may be implemented with a singleconnection to other devices of system 100 (e.g., via an Ethernet cablewith power over Ethernet, an integral power cable, and/or othercommunication and/or power transmission conduits integrated into asingle interface cable).

In various embodiments, sonar system 110 may be configured to providemany different display views from a variety of selectable perspectives,including down imaging, side imaging, and/or three dimensional imaging,all using the same hardware but with different selectable configurationsand/or processing methods, as described herein. In some embodiments,sonar system 110 may be implemented with a single transducer assemblyhousing incorporating a multichannel transducer and associatedelectronics. Such embodiments can reduce overall system cost because,for example, a multi-way interface cable is not needed. Such embodimentsmay also provide improved image quality by locating transmission andreceiver electronics close to their corresponding transmission andreceive channels, which can drastically improve signal to noise relativeto systems that transmit and/or receive analog signals over longcabling.

In general, embodiments of sonar system 110 may be configured totransmit relatively wide fan-shaped acoustic beams using a singletransmission channel and/or element of a multichannel transducer,receive similarly shaped acoustic returns using multiple receivechannels and/or elements of the multichannel transducer, and to performbeamforming and/or interferometry processing on the acoustic returns toproduce high quality two and/or three dimensional sonar imagery, asdescribed herein. In some embodiments, one or more sonar transmitters ofsonar system 110 may be configured to use chirp signals to improve rangeresolution and hence reduce ambiguities typically inherent ininterferometry processing techniques.

In some embodiments, sonar system 110 may be implemented with optionalorientation and/or position sensors (e.g., similar to orientation sensor140, gyroscope/accelerometer 144, and/or GNSS 146) that may beincorporated within the transducer assembly housing to provide threedimensional orientations and/or positions of the transducer assemblyand/or multichannel transducer for use when processing or postprocessing sonar data for display. The sensor information can be used tocorrect for movement of the transducer assembly between ensonificationsto provide improved alignment of corresponding acoustic returns/samples,for example, and/or to generate imagery based on the measuredorientations and/or positions of the transducer assembly. In otherembodiments, an external orientation and/or position sensor can be usedalone or in combination with an integrated sensor or sensors.

In embodiments where sonar system 110 is implemented with a positionsensor, sonar system 110 may be configured to provide a variety of sonardata and/or imagery enhancements. For example, sonar system 110 may beconfigured to provide accurate positioning of waypoints remote frommobile system 101 without having to estimate positions using, forexample, water depth and range. Similarly, sonar system 110 may beconfigured to provide accurate two and/or three dimensional display of aseries of sonar data; without position data, a sonar system typicallyassumes a straight track, which can cause image artifacts and/or otherinaccuracies in corresponding sonar data and/or imagery. Additionally,when implemented with a position sensor and/or interfaced with a remotebut relatively fixed position sensor (e.g., GNSS 146), sonar system 110may be configured to generate accurate and detailed bathymetric views ofa water bed or floor.

In embodiments where sonar system is implemented with an orientationand/or position sensor, sonar system 110 may be configured to store suchlocation/position information along with other sensor information(acoustic returns, temperature measurements, text descriptions, waterdepth, altitude, mobile structure speed, and/or other sensor and/orcontrol information) available to system 100. In some embodiments,controller 130 may be configured to generate a look up table so that auser can select desired configurations of sonar system 110 for aparticular location or to coordinate with some other sensor information.Alternatively, an automated adjustment algorithm can be used to selectoptimum configurations based on the sensor information.

For example, in one embodiment, mobile structure 101 may be located inan area identified on an chart using position data, a user may haveselected a user setting for a configuration of sonar system 110, andcontroller 130 may be configured to control an actuator and/or otherwiseimplement the configuration for sonar system 110 (e.g., to set aparticular orientation). In another embodiment, controller 130 may beconfigured to determine water depth and/or altitude, and use such datato control an orientation of sonar system 110 to maintain an optimumorientation for the reported depths/altitudes. In yet anotherembodiment, a user may be searching for fish in a wide area and mayselect a configuration setting that will adjust a transducer assemblyconfiguration to ensonify a relatively broad, shallow area. In stillanother embodiment, controller 130 may be configured to receiveorientation measurements for mobile structure 101. In such embodiment,controller 130 may be configured to control the actuators associatedwith the transducer assembly to maintain its orientation relative to,for example, the water surface, and thus improve the displayed sonarimages (e.g., by ensuring consistently oriented acoustic beams and/orproper registration of a series of acoustic returns). In variousembodiments, controller 130 may be configured to control steeringsensor/actuator 150 and/or propulsion system 170 to adjust a positionand/or orientation of mobile structure 101 to help ensure properregistration of a series of acoustic returns, sonar data, and/or sonarimagery.

Although FIG. 1A shows various sensors and/or other components of system100 separate from sonar system 110, in other embodiments, any one orcombination of sensors and components of system 100 may be integratedwith a sonar assembly, an actuator, a transducer module, and/or othercomponents of sonar system 110. For example, orientation sensor 140 maybe integrated with a transducer module of sonar system 110 and beconfigured to provide measurements of an absolute and/or relativeorientation (e.g., a roll, pitch, and/or yaw) of the transducer moduleto controller 130 and/or user interface 120, both of which may also beintegrated with sonar system 110.

User interface 120 may be implemented as a display, a touch screen, akeyboard, a mouse, a joystick, a knob, a steering wheel, a ship's wheelor helm, a yoke, and/or any other device capable of accepting user inputand/or providing feedback to a user. In various embodiments, userinterface 120 may be adapted to provide user input (e.g., as a type ofsignal and/or sensor information) to other devices of system 100, suchas controller 130. User interface 120 may also be implemented with oneor more logic devices that may be adapted to execute instructions, suchas software instructions, implementing any of the various processesand/or methods described herein. For example, user interface 120 may beadapted to form communication links, transmit and/or receivecommunications (e.g., sensor signals, control signals, sensorinformation, user input, and/or other information), determine variouscoordinate frames and/or orientations, determine parameters for one ormore coordinate frame transformations, and/or perform coordinate frametransformations, for example, or to perform various other processesand/or methods.

In various embodiments, user interface 120 may be adapted to accept userinput, for example, to form a communication link, to select a particularwireless networking protocol and/or parameters for a particular wirelessnetworking protocol and/or wireless link (e.g., a password, anencryption key, a MAC address, a device identification number, a deviceoperation profile, parameters for operation of a device, and/or otherparameters), to select a method of processing sensor signals todetermine sensor information, to adjust a position and/or orientation ofan articulated sensor, and/or to otherwise facilitate operation ofsystem 100 and devices within system 100. Once user interface 120accepts a user input, the user input may be transmitted to other devicesof system 100 over one or more communication links.

In one embodiment, user interface 120 may be adapted to receive a sensoror control signal (e.g., from orientation sensor 140 and/or steeringsensor/actuator 150) over communication links formed by one or moreassociated logic devices, for example, and display sensor and/or otherinformation corresponding to the received sensor or control signal to auser. In related embodiments, user interface 120 may be adapted toprocess sensor and/or control signals to determine sensor and/or otherinformation. For example, a sensor signal may include an orientation, anangular velocity, an acceleration, a speed, and/or a position of mobilestructure 101. In such embodiment, user interface 120 may be adapted toprocess the sensor signals to determine sensor information indicating anestimated and/or absolute roll, pitch, and/or yaw (attitude and/orrate), and/or a position or series of positions of mobile structure 101,for example, and display the sensor information as feedback to a user.In one embodiment, user interface 120 may be adapted to display a timeseries of various sensor information and/or other parameters as part ofor overlaid on a graph or map, which may be referenced to a positionand/or orientation of mobile structure 101. For example, user interface120 may be adapted to display a time series of positions, headings,and/or orientations of mobile structure 101 and/or other elements ofsystem 100 (e.g., a transducer assembly and/or module of sonar system110) overlaid on a geographical map, which may include one or moregraphs indicating a corresponding time series of actuator controlsignals, sensor information, and/or other sensor and/or control signals.

In some embodiments, user interface 120 may be adapted to accept userinput including a user-defined target heading, route, and/or orientationfor a transducer module, for example, and to generate control signalsfor steering sensor/actuator 150 and/or propulsion system 170 to causemobile structure 101 to move according to the target heading, route,and/or orientation. In further embodiments, user interface 120 may beadapted to accept user input including a user-defined target attitudefor an actuated device (e.g., sonar system 110) coupled to mobilestructure 101, for example, and to generate control signals foradjusting an orientation of the actuated device according to the targetattitude. More generally, user interface 120 may be adapted to displaysensor information to a user, for example, and/or to transmit sensorinformation and/or user input to other user interfaces, sensors, orcontrollers of system 100, for instance, for display and/or furtherprocessing.

Controller 130 may be implemented as any appropriate logic device (e.g.,processing device, microcontroller, processor, application specificintegrated circuit (ASIC), field programmable gate array (FPGA), memorystorage device, memory reader, or other device or combinations ofdevices) that may be adapted to execute, store, and/or receiveappropriate instructions, such as software instructions implementing acontrol loop for controlling various operations of sonar system 110,steering sensor/actuator 150, mobile structure 101, and/or system 100,for example. Such software instructions may also implement methods forprocessing sensor signals, determining sensor information, providinguser feedback (e.g., through user interface 120), querying devices foroperational parameters, selecting operational parameters for devices, orperforming any of the various operations described herein (e.g.,operations performed by logic devices of various devices of system 100).

In addition, a machine readable medium may be provided for storingnon-transitory instructions for loading into and execution by controller130. In these and other embodiments, controller 130 may be implementedwith other components where appropriate, such as volatile memory,non-volatile memory, one or more interfaces, and/or various analogand/or digital components for interfacing with devices of system 100.For example, controller 130 may be adapted to store sensor signals,sensor information, parameters for coordinate frame transformations,calibration parameters, sets of calibration points, and/or otheroperational parameters, over time, for example, and provide such storeddata to a user using user interface 120. In some embodiments, controller130 may be integrated with one or more user interfaces (e.g., userinterface 120), and, in one embodiment, may share a communication moduleor modules. As noted herein, controller 130 may be adapted to executeone or more control loops for actuated device control, steering control(e.g., using steering sensor/actuator 150) and/or performing othervarious operations of mobile structure 101 and/or system 100. In someembodiments, a control loop may include processing sensor signals and/orsensor information in order to control one or more operations of sonarsystem 110, mobile structure 101, and/or system 100.

Orientation sensor 140 may be implemented as one or more of a compass,float, accelerometer, and/or other device capable of measuring anorientation of mobile structure 101 (e.g., magnitude and direction ofroll, pitch, and/or yaw, relative to one or more reference orientationssuch as gravity and/or Magnetic North) and providing such measurementsas sensor signals that may be communicated to various devices of system100. In some embodiments, orientation sensor 140 may be adapted toprovide heading measurements for mobile structure 101. In otherembodiments, orientation sensor 140 may be adapted to provide roll,pitch, and/or yaw rates for mobile structure 101 (e.g., using a timeseries of orientation measurements). Orientation sensor 140 may bepositioned and/or adapted to make orientation measurements in relationto a particular coordinate frame of mobile structure 101, for example.

Speed sensor 142 may be implemented as an electronic pitot tube, meteredgear or wheel, water speed sensor, wind speed sensor, a wind velocitysensor (e.g., direction and magnitude) and/or other device capable ofmeasuring or determining a linear speed of mobile structure 101 (e.g.,in a surrounding medium and/or aligned with a longitudinal axis ofmobile structure 101) and providing such measurements as sensor signalsthat may be communicated to various devices of system 100. In someembodiments, speed sensor 142 may be adapted to provide a velocity of asurrounding medium relative to sensor 142 and/or mobile structure 101.

Gyroscope/accelerometer 144 may be implemented as one or more electronicsextants, semiconductor devices, integrated chips, accelerometersensors, accelerometer sensor systems, or other devices capable ofmeasuring angular velocities/accelerations and/or linear accelerations(e.g., direction and magnitude) of mobile structure 101 and providingsuch measurements as sensor signals that may be communicated to otherdevices of system 100 (e.g., user interface 120, controller 130).Gyroscope/accelerometer 144 may be positioned and/or adapted to makesuch measurements in relation to a particular coordinate frame of mobilestructure 101, for example. In various embodiments,gyroscope/accelerometer 144 may be implemented in a common housingand/or module to ensure a common reference frame or a knowntransformation between reference frames.

GNSS 146 may be implemented as a GNSS and/or global positioningsatellite (GPS) receiver and/or other device capable of determiningabsolute and/or relative position of mobile structure 101 based onwireless signals received from space-born and/or terrestrial sources,for example, and capable of providing such measurements as sensorsignals that may be communicated to various devices of system 100. Insome embodiments, GNSS 146 may be adapted to determine a velocity,speed, and/or yaw rate of mobile structure 101 (e.g., using a timeseries of position measurements), such as an absolute velocity and/or ayaw component of an angular velocity of mobile structure 101. In variousembodiments, one or more logic devices of system 100 may be adapted todetermine a calculated speed of mobile structure 101 and/or a computedyaw component of the angular velocity from such sensor information.

Steering sensor/actuator 150 may be adapted to physically adjust aheading of mobile structure 101 according to one or more controlsignals, user inputs, and/or a stabilized attitude estimates provided bylogic device of system 100, such as controller 130. Steeringsensor/actuator 150 may include one or more actuators and controlsurfaces (e.g., a rudder or other type of steering mechanism) of mobilestructure 101, and may be adapted to physically adjust the controlsurfaces to a variety of positive and/or negative steeringangles/positions.

Propulsion system 170 may be implemented as a propeller, turbine, orother thrust-based propulsion system, a mechanical wheeled and/ortracked propulsion system, a sail-based propulsion system, and/or othertypes of propulsion systems that can be used to provide motive force tomobile structure 101. In some embodiments, propulsion system 170 may benon-articulated, for example, such that the direction of motive forceand/or thrust generated by propulsion system 170 is fixed relative to acoordinate frame of mobile structure 101. Non-limiting examples ofnon-articulated propulsion systems include, for example, an inboardmotor for a watercraft with a fixed thrust vector, for example, or afixed aircraft propeller or turbine. In other embodiments, propulsionsystem 170 may be articulated, for example, and may be coupled to and/orintegrated with steering sensor/actuator 150, for example, such that thedirection of generated motive force and/or thrust is variable relativeto a coordinate frame of mobile structure 101. Non-limiting examples ofarticulated propulsion systems include, for example, an outboard motorfor a watercraft, an inboard motor for a watercraft with a variablethrust vector/port (e.g., used to steer the watercraft), a sail, or anaircraft propeller or turbine with a variable thrust vector, forexample.

Other modules 180 may include other and/or additional sensors,actuators, communications modules/nodes, and/or user interface devicesused to provide additional environmental information of mobile structure101, for example. In some embodiments, other modules 180 may include ahumidity sensor, a wind and/or water temperature sensor, a barometer, aradar system, a visible spectrum camera, an infrared camera, and/orother environmental sensors providing measurements and/or other sensorsignals that can be displayed to a user and/or used by other devices ofsystem 100 (e.g., controller 130) to provide operational control ofmobile structure 101 and/or system 100 that compensates forenvironmental conditions, such as wind speed and/or direction, swellspeed, amplitude, and/or direction, and/or an object in a path of mobilestructure 101, for example. In some embodiments, other modules 180 mayinclude one or more actuated devices (e.g., spotlights, cameras, radars,sonars, and/or other actuated devices) coupled to mobile structure 101,where each actuated device includes one or more actuators adapted toadjust an orientation of the device, relative to mobile structure 101,in response to one or more control signals (e.g., provided by controller130).

In general, each of the elements of system 100 may be implemented withany appropriate logic device (e.g., processing device, microcontroller,processor, application specific integrated circuit (ASIC), fieldprogrammable gate array (FPGA), memory storage device, memory reader, orother device or combinations of devices) that may be adapted to execute,store, and/or receive appropriate instructions, such as softwareinstructions implementing a method for providing sonar data and/orimagery, for example, or for transmitting and/or receivingcommunications, such as sensor signals, sensor information, and/orcontrol signals, between one or more devices of system 100. In oneembodiment, such method may include instructions to receive anorientation, acceleration, position, and/or speed of mobile structure101 and/or sonar system 110 from various sensors, to determine atransducer orientation adjustment (e.g., relative to a desiredtransducer orientation) from the sensor signals, and/or to control anactuator to adjust a transducer orientation accordingly, for example, asdescribed herein. In a further embodiment, such method may includeinstructions for forming one or more communication links between variousdevices of system 100.

In addition, one or more machine readable mediums may be provided forstoring non-transitory instructions for loading into and execution byany logic device implemented with one or more of the devices of system100. In these and other embodiments, the logic devices may beimplemented with other components where appropriate, such as volatilememory, non-volatile memory, and/or one or more interfaces (e.g.,inter-integrated circuit (I2C) interfaces, mobile industry processorinterfaces (MIPI), joint test action group (JTAG) interfaces (e.g., IEEE1149.1 standard test access port and boundary-scan architecture), and/orother interfaces, such as an interface for one or more antennas, or aninterface for a particular type of sensor).

Each of the elements of system 100 may be implemented with one or moreamplifiers, modulators, phase adjusters, beamforming components, digitalto analog converters (DACs), analog to digital converters (ADCs),various interfaces, antennas, transducers, and/or other analog and/ordigital components enabling each of the devices of system 100 totransmit and/or receive signals, for example, in order to facilitatewired and/or wireless communications between one or more devices ofsystem 100. Such components may be integrated with a correspondingelement of system 100, for example. In some embodiments, the same orsimilar components may be used to perform one or more sensormeasurements, as described herein. For example, the same or similarcomponents may be used to create an acoustic pulse (e.g., a transmissioncontrol signal and/or a digital shaping control signal), convert theacoustic pulse to an excitation signal (e.g., a shaped or unshapedtransmission signal) and transmit it to a sonar transducer element toproduce an acoustic beam, receive an acoustic return (e.g., a sound wavereceived by the sonar transducer element and/or corresponding electricalsignals from the sonar transducer element), convert the acoustic returnto acoustic return data, and/or store sensor information, configurationdata, and/or other data corresponding to operation of a sonar system, asdescribed herein. Sensor signals, control signals, and other signals maybe communicated among elements of system 100 using a variety of wiredand/or wireless communication techniques, including voltage signaling,Ethernet, WiFi, Bluetooth, Zigbee, Xbee, Micronet, or other mediumand/or short range wired and/or wireless networking protocols and/orimplementations, for example. In such embodiments, each element ofsystem 100 may include one or more modules supporting wired, wireless,and/or a combination of wired and wireless communication techniques.

In some embodiments, various elements or portions of elements of system100 may be integrated with each other, for example, or may be integratedonto a single printed circuit board (PCB) to reduce system complexity,manufacturing costs, power requirements, and/or timing errors betweenthe various sensor measurements. For example, gyroscope/accelerometer144 and controller 130 may be configured to share one or morecomponents, such as a memory, a logic device, a communications module,and/or other components, and such sharing may act to reduce and/orsubstantially eliminate such timing errors while reducing overall systemcomplexity and/or cost.

Each element of system 100 may include one or more batteries or otherelectrical power storage devices, for example, and may include one ormore solar cells or other electrical power generating devices (e.g., awind or water-powered turbine, or a generator producing electrical powerfrom motion of one or more elements of system 100). In some embodiments,one or more of the devices may be powered by a power source for mobilestructure 101, using one or more power leads. Such power leads may alsobe used to support one or more communication techniques between elementsof system 100.

In various embodiments, a logic device of system 100 (e.g., oforientation sensor 140 and/or other elements of system 100) may beadapted to determine parameters (e.g., using signals from variousdevices of system 100) for transforming a coordinate frame of sonarsystem 110 and/or other sensors of system 100 to/from a coordinate frameof mobile structure 101, at-rest and/or in-motion, and/or othercoordinate frames, as described herein. One or more logic devices ofsystem 100 may be adapted to use such parameters to transform acoordinate frame of sonar system 110 and/or other sensors of system 100to/from a coordinate frame of orientation sensor 140 and/or mobilestructure 101, for example. Furthermore, such parameters may be used todetermine and/or calculate one or more adjustments to an orientation ofsonar system 110 that would be necessary to physically align acoordinate frame of sonar system 110 with a coordinate frame oforientation sensor 140 and/or mobile structure 101, for example, or anabsolute coordinate frame. Adjustments determined from such parametersmay be used to selectively power adjustment servos/actuators (e.g., ofsonar system 110 and/or other sensors or elements of system 100), forexample, or may be communicated to a user through user interface 120, asdescribed herein.

FIG. 1B illustrates a diagram of system 100B in accordance with anembodiment of the disclosure. In the embodiment shown in FIG. 1B, system100B may be implemented to provide sonar data and/or imagery for usewith operation of mobile structure 101, similar to system 100 of FIG.1B. For example, system 100B may include sonar system 110, integrateduser interface/controller 120/130, secondary user interface 120,steering sensor/actuator 150, sensor cluster 160 (e.g., orientationsensor 140, gyroscope/accelerometer 144, and/or GNSS 146), and variousother sensors and/or actuators. In the embodiment illustrated by FIG.1B, mobile structure 101 is implemented as a motorized boat including ahull 105 b, a deck 106 b, a transom 107 b, a mast/sensor mount 108 b, arudder 152, an inboard motor 170, and an actuated sonar system 110coupled to transom 107 b. In other embodiments, hull 105 b, deck 106 b,mast/sensor mount 108 b, rudder 152, inboard motor 170, and variousactuated devices may correspond to attributes of a passenger aircraft orother type of vehicle, robot, or drone, for example, such as anundercarriage, a passenger compartment, an engine/engine compartment, atrunk, a roof, a steering mechanism, a headlight, a radar system, and/orother portions of a vehicle.

As depicted in FIG. 1B, mobile structure 101 includes actuated sonarsystem 110, which in turn includes transducer assembly 112 coupled totransom 107 b of mobile structure 101 through assembly bracket/actuator116 and transom bracket/electrical conduit 114. In some embodiments,assembly bracket/actuator 116 may be implemented as a roll, pitch,and/or yaw actuator, for example, and may be adapted to adjust anorientation of transducer assembly 112 according to control signalsand/or an orientation (e.g., roll, pitch, and/or yaw) or position ofmobile structure 101 provided by user interface/controller 120/130. Forexample, user interface/controller 120/130 may be adapted to receive anorientation of transducer assembly 112 configured to ensonify a portionof surrounding water and/or a direction referenced to an absolutecoordinate frame, and to adjust an orientation of transducer assembly112 to retain ensonification of the position and/or direction inresponse to motion of mobile structure 101, using one or moreorientations and/or positions of mobile structure 101 and/or othersensor information derived by executing various methods describedherein. In another embodiment, user interface/controller 120/130 may beconfigured to adjust an orientation of transducer assembly 112 to directsonar transmissions from transducer assembly 112 substantially downwardsand/or along an underwater track during motion of mobile structure 101.In such embodiment, the underwater track may be predetermined, forexample, or may be determined based on criteria parameters, such as aminimum allowable depth, a maximum ensonified depth, a bathymetricroute, and/or other criteria parameters.

In one embodiment, user interfaces 120 may be mounted to mobilestructure 101 substantially on deck 106 b and/or mast/sensor mount 108b. Such mounts may be fixed, for example, or may include gimbals andother leveling mechanisms/actuators so that a display of user interfaces120 stays substantially level with respect to a horizon and/or a “down”vector (e.g., to mimic typical user head motion/orientation). In anotherembodiment, at least one of user interfaces 120 may be located inproximity to mobile structure 101 and be mobile throughout a user level(e.g., deck 106 b) of mobile structure 101. For example, secondary userinterface 120 may be implemented with a lanyard and/or other type ofstrap and/or attachment device and be physically coupled to a user ofmobile structure 101 so as to be in proximity to mobile structure 101.In various embodiments, user interfaces 120 may be implemented with arelatively thin display that is integrated into a PCB of thecorresponding user interface in order to reduce size, weight, housingcomplexity, and/or manufacturing costs.

As shown in FIG. 1B, in some embodiments, speed sensor 142 may bemounted to a portion of mobile structure 101, such as to hull 105 b, andbe adapted to measure a relative water speed. In some embodiments, speedsensor 142 may be adapted to provide a thin profile to reduce and/oravoid water drag. In various embodiments, speed sensor 142 may bemounted to a portion of mobile structure 101 that is substantiallyoutside easy operational accessibility. Speed sensor 142 may include oneor more batteries and/or other electrical power storage devices, forexample, and may include one or more water-powered turbines to generateelectrical power. In other embodiments, speed sensor 142 may be poweredby a power source for mobile structure 101, for example, using one ormore power leads penetrating hull 105 b. In alternative embodiments,speed sensor 142 may be implemented as a wind velocity sensor, forexample, and may be mounted to mast/sensor mount 108 b to haverelatively clear access to local wind.

In the embodiment illustrated by FIG. 1B, mobile structure 101 includesdirection/longitudinal axis 102, direction/lateral axis 103, anddirection/vertical axis 104 meeting approximately at mast/sensor mount108 b (e.g., near a center of gravity of mobile structure 101). In oneembodiment, the various axes may define a coordinate frame of mobilestructure 101 and/or sensor cluster 160. Each sensor adapted to measurea direction (e.g., velocities, accelerations, headings, or other statesincluding a directional component) may be implemented with a mount,actuators, and/or servos that can be used to align a coordinate frame ofthe sensor with a coordinate frame of any element of system 100B and/ormobile structure 101. Each element of system 100B may be located atpositions different from those depicted in FIG. 1B. Each device ofsystem 100B may include one or more batteries or other electrical powerstorage devices, for example, and may include one or more solar cells orother electrical power generating devices. In some embodiments, one ormore of the devices may be powered by a power source for mobilestructure 101. As noted herein, each element of system 100B may beimplemented with an antenna, a logic device, and/or other analog and/ordigital components enabling that element to provide, receive, andprocess sensor signals and interface or communicate with one or moredevices of system 100B. Further, a logic device of that element may beadapted to perform any of the methods described herein.

FIG. 2A illustrates a diagram of a multichannel sonar system 200 inaccordance with an embodiment of the disclosure. In the embodiment shownin FIG. 2A, multichannel sonar system 200 includes a transducer assembly210 that can be coupled to a user interface (e.g., user interface 120 ofFIG. 1A) and/or a power source through a single I/O cable 214. As shown,transducer assembly 210 may include one or more controllers (e.g., sonarsystem controller 220 and/or co-controller 222), transducers (e.g.,multichannel transducer 250 and/or transducer 264), other sensors (e.g.,orientation/position sensor 240 and/or water temperature sensor 266),and/or other devices facilitating operation of system 200 all disposedwithin a common housing 211. In other embodiments, one or more of thedevices shown in FIG. 2A may be integrated with a remote user interfaceand communicate with remaining devices within transducer assembly 210through one or more data and/or power cables similar to I/O cable 214.

Controller 220 and/or co-controller 222 may each be implemented as anyappropriate logic device (e.g., processing device, microcontroller,processor, application specific integrated circuit (ASIC), fieldprogrammable gate array (FPGA), memory storage device, memory reader, orother device or combinations of devices) that may be adapted to execute,store, and/or receive appropriate instructions, such as softwareinstructions implementing a control loop for controlling variousoperations of transducer assembly 210 and/or system 200, for example,similar to controller 130. In typical embodiments, controller 220 may betasked with overseeing general operation of transducer assembly 210,generating sonar imagery from sonar data, correlating sensor data withsonar data/imagery, communicating operational parameters and/or sensorinformation with other devices through I/O cable 214, and/or othernon-time-critical operations of system 200. In such embodiments,co-controller 222 may be implemented with relatively high resolutiontiming circuitry capable of generating digital transmission and/orsampling control signals for operating transmitters, receivers,transceivers, signal conditioners, and/or other devices of transducerassembly 210, for example, and other time critical operations of system200, such as per-sample digital beamforming and/or interferometryoperations applied to sonar returns from multichannel transducer 250, asdescribed herein. In some embodiments, controller 220 and co-controller222 may be integrated together, for example, or may be implemented in adistributed manner across a number of individual controllers.

Transmitter 230 may be implemented with one or more digital to analogconverters (DACs), signal shaping circuits, filters, phase adjusters,signal conditioning elements, amplifiers, timing circuitry, logicdevices, and/or other digital and/or analog electronics configured toaccept digital control signals from co-controller 222 and to generatetransmission signals to excite a transmission channel/transducer elementof multichannel transducer 250 (e.g., transmission channel 260) toproduce one or more acoustic beams. In some embodiments, operation oftransmitter 230 (e.g., amplification, frequency dependent filtering,transmit signal frequency, duration, shape, and/or timing/triggering,and/or other signal attributes), may be controlled (e.g., through use ofvarious control signals) by co-controller 222, as described herein.

Each of receivers 232 (e.g., for N channels as shown) may be implementedwith one or more analog to digital converters (ADCs), filters, phaseadjusters, signal conditioning elements, amplifiers, timing circuitry,logic devices, and/or other digital and/or analog electronics configuredto accept analog acoustic returns from a corresponding receivechannel/transducer element of multichannel transducer 250 (e.g., receivechannels 262), convert the analog acoustic returns into digital acousticreturns, and provide the digital acoustic returns to co-controller 222.In some embodiments, operation of each receiver 232 (e.g.,amplification, frequency dependent filtering, basebanding, sampleresolution, duration, and/or timing/triggering, and/or other ADC/signalattributes) may be controlled by co-controller 222. For example,co-controller 222 may be configured to use receivers 232 to convert anacoustic return into a digital acoustic return comprising one or moredigital baseband transmissions that are then provided to co-controller222. In some embodiments, receivers 232 may be configured to low-pass orotherwise filter, amplify, decimate, and/or otherwise process theacoustic and/or digital acoustic returns (e.g., using analog and/ordigital signal processing) prior to providing the digital acousticreturns to co-controller 222. In other embodiments, receivers 232 may beconfigured to provide substantially unprocessed (e.g., raw) analogand/or digital acoustic returns to co-controller 222 for further signalprocessing, as described herein. In further embodiments, transmitter 230and one or more of receivers 232 may be integrated into a singletransceiver.

In the embodiment shown in FIG. 2A, multichannel transducer 250 includesmultiple transducer elements and/or transmission/receive channels thatmay be operated substantially independently of each other and beconfigured to emit acoustic beams and receive acoustic returns throughemission surface 212 of housing 211. In some embodiments, multichanneltransducer 250 may include a single transmission channel 260 and,separately, multiple receive channels 262. In other embodiments,multichannel transducer 250 may include multiple transmission channels.In further embodiments, transmission channel 260 may be implemented asboth a transmission channel and a receive channel though use of atransceiver (e.g., similar to transceiver 234). In general, transmissionchannel 260 may be implemented as one, two, or many separate transducerelements configured to produce one or more acoustic beams. Each ofreceive channels 262 may also be implemented as one, two, or manyseparate transducer elements, but configured to receive acousticreturns. The effective volumetric shapes of the acoustic beams andacoustic returns may be determined by the shapes and arrangements oftheir corresponding transducer elements, as described herein. In variousembodiments, the various channels of multichannel transducer 250 may bearranged to facilitate multichannel processing, such as beamforming,interferometry, inter-beam interpolation, and/or other types ofmultichannel processing used to produce sonar data and/or imagery.

For example, in one embodiment, multichannel transducer 250 may beimplemented with multiple transmission channels 260 arranged in a phasedarray to allow electronic steering of relatively narrow acoustic beams(relative to those produced by a single transmission channel 260) withina relatively wide range of transmission angles. In such embodiments,transducer assembly 210 may be configured to use such electronicallysteered beams to improve signal-to-noise in resulting sonar data and/orimagery and/or to improve rejection of false targets detected in thecorresponding acoustic returns. A related and less complex embodimentcould be a transmission array implemented without phasing such that theresulting acoustic beam width can be adjusted by including or excludingtransmission channels and/or elements. For example, such embodimentscould be used to alternate between operation with deep verses shallowwater where the acoustic beams could be switched between relativelynarrow for deep water and relative wide for shallow water.

In some embodiments, transducer assembly 210 may be implemented with oneor more additional transducers (e.g., transducer 264) separate frommultichannel transducer 250, and serviced by separatetransmitter/receiver electronics similar to transmitter 230 and/orreceivers 232 (e.g., transceiver 234, which may include high voltageprotection circuitry and/or transmit/receive switching to enabletransmission and reception over the same leads 218). In variousembodiments, operation of transceiver 234 and/or transducer 264 (e.g.,and its constituent transducer elements) may be controlled byco-controller 222, similar to control of transmitter 230 and/orreceivers 232 described herein. Typically, transceiver 234 and/ortransducer 264 may be configured to produce acoustic beams adapted toreduce or eliminate interference with operation of multichanneltransducer 250, such as by using a substantially different transmissionfrequency, timing, and/or shape, and/or by aiming the acoustic beams ina substantially non-interfering direction. In alternative embodiments,transceiver 234 and/or transducer 264 may be configured to generateacoustic beams that produce acoustic returns in multichannel transducer250, similar to operation of transmitter 230 and transmission channel260, but from an oblique angle relative to multichannel transducer 250.In such embodiments, the oblique acoustic returns may be used togenerate sonar imagery with increased spatial differentiation and/orcontrast between objects in the water column ensonified by transducerassembly 210.

Transducer assembly 210 may include water temperature sensor 266, whichmay be a digital and/or analog thermometer, sound cell, and/or otheranalog or digital device configured to measure a temperature of waternear emission surface 212 and provide a corresponding sensor signal tosignal conditioner 236 and/or co-controller 222. For example, soundvelocity and/or attenuation in water is at least partially dependent onwater temperature, and so measured water temperatures may be used todetermine accurate measurements of spatial displacements (e.g., depths,object dimensions, and/or other spatial displacements) ensonified bytransducer assembly 210. Signal conditioner 236 may be one or more ADCs,filters, signal conditioning elements, amplifiers, timing circuitry,logic devices, and/or other digital and/or analog electronics configuredto accept sensor signals from water temperature sensor 266, filter,amplify, linearize, and/or otherwise condition the sensor signals, andprovide the conditioned sensor signals to co-controller 222. In someembodiments, signal conditioner 236 may be configured to providereference signals and/or other control signals to water temperaturesensor 266 to enable operation of a particular type of water temperaturesensor, for example, and may be controlled by co-controller 222.

In FIG. 2A, each of multichannel transducer 250, transducer 262, and/orwater temperature sensor 266 are coupled to their electronics over leads218 and through shielding 219. In various embodiments, leads 218 and/orshielding 219 may be implemented as one or more shielded transmissionlines configured to convey analog and/or digital signals between thevarious elements while shielding the transducers and/or temperaturesensor from electromagnetic interference from each other, other elementsof transducer assembly 210, and/or external sources. In someembodiments, leads 218 and shielding 219 may be integrated together toform a transmission system. For example, shielding 219 may be configuredto provide a ground plane/return for signals conveyed by leads 218. Inone embodiment, leads 218 may be implemented as a first conductiveribbon with multiple electrically isolated conductive traces (e.g., onefor each channel/sensor), for example, and shielding 219 may beimplemented as a second conductive ribbon with one or more relativelywide conductive traces electrically coupled to multiple channels ofmultichannel transducer 250, transducer 264, and/or water temperaturesensor 266.

As shown, transducer assembly 210 may be implemented with sonar systemorientation/position sensor 240. Orientation/position sensor 240 may beimplemented as one or more orientation sensors, GNSS/GPS sensors,differential GNSS/GPS sensors, orientation/position referencetransducers and/or optical sensor (e.g., for actuators), and/or othersensors configured to measure a relative and/or absolute orientationand/or position of transducer assembly 210 and/or multichanneltransducer 250 and provide such measurements to controller 220 and/orco-controller 222. In some embodiments, controller 220 and/orco-controller 222 may be configured to combine sonar data and/or imageryaccording to such measurements and/or measurements of an orientationand/or position of a coupled mobile structure to produce combined sonardata and/or imagery, such as multiple co-registered sonar images, forexample, and/or three dimensional sonar images. In other embodiments,controller 220 and/or co-controller 222 may be configured to useorientation and/or position measurements of transducer assembly 210and/or a coupled mobile structure to control one or more actuators(e.g., other devices 280) to adjust a position and/or orientation oftransducer assembly 210 and ensonify a particular position and/ororientation using transducer assembly 210 and/or multichannel transducer250.

Other devices 280 may include other and/or additional sensors, sensorarrays, actuators, logic devices, communications modules/nodes, powerdistribution components, and/or user interface devices used to provideadditional environmental information and/or configuration parameters,for example, and/or to adjust a position and/or orientation oftransducer assembly 210. In some embodiments, other devices 280 mayinclude a visible spectrum camera, an infrared camera, and/or otherenvironmental sensors providing measurements and/or other sensor signalsthat can be displayed to a user and/or used by other devices oftransducer assembly 210 (e.g., controller 220) to provide operationalcontrol of transducer assembly 210. In some embodiments, other devices280 may include one or more actuators adapted to adjust an orientation(e.g., roll, pitch, and/or yaw) and/or a position (longitudinal,lateral, and/or vertical) of transducer assembly 210, multichanneltransducer 250, and/or transducer 264, relative to a coupled mobilestructure, in response to one or more control signals (e.g., provided bycontroller 220). In other embodiments, other devices 280 may include oneor more brackets, such as a transom bracket, adapted to couple housing211 to a mobile structure.

In various embodiments, transducer assembly 210 may be implemented in asingle housing 211 with a single interface (e.g., I/O cable 214) tosimplify installation and use. For example, I/O cable 214 may beimplemented as a power-over-Ethernet (POE) cable supporting transmissionof both communications and power between transducer assembly 210 andelements of a coupled mobile structure. Such communications and/or powermay be delivered over leads 216 to power supply 215 and/or controller220. Power supply 215 may be implemented as one or more powerconditioners, line filters, switching power supplies, DC to DCconverters, voltage regulators, power storage devices (e.g., batteries),and/or other power supply devices configured to receive power over leads216 and/or distribute power to the various other elements of transducerassembly 210.

In various sensor applications, including sonar, radar, and/or othertransmission signal-based sensor systems, it is advantageous to be ableto control the overall shape of the transmission signal (e.g., a burstof signals). From a processing perspective, shaping the transmissionsignal can reduce the number and magnitude of artifacts that typicallyoccur along the range direction of the sensor system, which improves thequality and accuracy of resulting imagery and collateral processing,such as reducing false target detection. From a power amplifier designperspective, the shaping can reduce transients and associated issueswith component saturation. From an electromagnetic compatibility (EMC)perspective, the shaping can reduce harmonics and associated spuriousinterference. Switching methods such as pulse width modulation (PWM) orpulse density modulation (PDM) require expensive fast switchingcomponents that can introduce unwanted harmonics and otherwise causedegradation in operation of a sensor system.

FIG. 2B illustrates a diagram of sonar transmitter 230 configured toimplement a digitally controlled method of shaping a transmission signalwithout a need for fast switching components, in accordance with anembodiment of the disclosure. In the embodiment shown in FIG. 2B, system201 includes co-controller 222 configured to provide a digital shapingcontrol signal over lead 281, and a transmission control signal overlead 282, to transmitter 230, which in turn is configured to provide ashaped transmission signal to load 260 over leads 218 a-b.

As shown in FIG. 2B, transmitter 230 may be implemented with shapingcircuit 286 (e.g., an emitter follower type circuit) that is operated byco-controller 222 through DAC 284. This arrangement digitally controlsthe proportion of a reference voltage (e.g., provided by power source291 over lead 292) that is presented to power amplifier 290 over lead293 and hence shapes the transmission signal (e.g., corresponding to atransmission control signal provided over lead 282 by co-controller222).

For example, in general operation, co-controller 222 may be configuredto provide two digital control signals to transmitter 230: a digitalshaping control signal over lead 281, and a transmission control signalover lead 282. Lead 281 may provide the digital shaping control signalto DAC 284 of transmitter 230, and DAC 284 may be configured to convertthe digital shaping control signal to a corresponding analog shapingcontrol signal that is provided to shaping circuit 286 over lead 285.Shaping circuit 286 may be configured to convert a reference voltage(e.g., provided by power source 291 of power amplifier 290) to a shapedvoltage corresponding to the analog shaping control signal, for example,and the shaped voltage may be provided to power amplifier 290 over lead293. Power amplifier 290 may be configured to convert the shaped voltageinto a shaped transmission signal corresponding to both the digitalshaping control signal and the transmission control signal provided byco-controller 222. Power amplifier 290 may also be configured to providethe shaped transmission signal to load 260 over leads 218 a-b, as shown.

DAC 284 may be implemented with one or more logic devices, filters,amplifiers, timing circuitry, and/or other digital and/or analogelectronics configured to convert the digital shaping control signal toa corresponding analog shaping control signal and provide the analogshaping control signal to shaping circuit 286. In some embodiments, DAC284 may be configured to use the digital shaping control signal directlyto charge one or more capacitors that are then controllably dischargedin order to convert the digital shaping control signal into acorresponding analog shaping control signal without reliance on adigital interface between co-controller 222 and DAC 284.

Shaping circuit 286 may be implemented with one or more transistors,filter arrangements, amplifier arrangements, and/or other digital and/oranalog electronics configured to receive an analog shaping controlsignal, convert a reference voltage to a corresponding shaped voltage,and provide the shaped voltage to power amplifier 290. In oneembodiment, shaping circuit 286 may be configured to provide currentgain and/or act as an analog current amplifier for the analog shapingcontrol signal. For example, shaping circuit 286 may be implemented withone or more bipolar junction transistors (BJTs) arranged in an emitterfollower and/or voltage buffer circuit, as shown. In some embodiments,shaping circuit 286 may include NPN BJT 287 a and PNP BJT 287 b withcoupled emitters and bases, with the bases coupled to receive the analogshaping control signal, one collector coupled to the reference voltage,and the other collector coupled to ground.

Power amplifier 290 may be implemented with one or more power sources,transformers, transistors, and/or other digital and/or analogelectronics configured to receive a shaped voltage from shaping circuit286 and convert the shaped voltage into a corresponding shapedtransmission signal. In some embodiments, power amplifier 290 may beimplemented with power source 291 configured to supply a referencevoltage and sufficient backing current to shaping circuit 286 in orderto generate a shaped transmission signal across leads 218 a-b using theshaped voltage supplied by shaping circuit 286, as described herein.

In one embodiment, power amplifier 290 may include transformer 294 andcurrent switches 297 a-b all configured to convert a shaped voltageprovided over lead 293 and a transmission control signal provided overlead 282 into a corresponding shaped transmission signal. In suchembodiments, transformer 294 may be implemented with a primary windingcoupled to the shaped voltage and current switches 297 a-b, and asecondary winding coupled to leads 218 a-b. The primary and secondarywindings may have the same or a different number of windings, forexample, and the number of windings may depend on the expected currentsand loads and may be configured to maximize the power delivered to load260. The primary winding may be center tapped, for example, or may betapped off-center to tune transmitter 230 to maximize the powerdelivered to load 260, and the tap may be coupled to the shaped voltageas shown. Ends of the primary winding may be coupled to switches 297a-b, which may be controlled by co-controller 222 using the transmissioncontrol signal provided over lead 282.

In one embodiment, the transmission control signal may include apositive signal component and a negative signal component transmitted ondifferent conductors of lead 282. The different conductors may be splitat node 296 and each coupled to control leads of current switches 297a-b. In some embodiments, current switches 297 a-b may be implementedfrom one or more MOSFETs, such as one or more N-channel inductivechannel MOSFETs, for example, and the control leads may correspond togates of the MOSFETs. In various embodiments, a positive voltage at acontrol lead of either current switch 297 a-b causes a first current topass through the primary winding of transformer 294 from the tap to thetop or bottom end and then to ground, and the amount of first current isdetermined, at least in part, by the shaped voltage provided by shapingcircuit 286, as shown and described. The first current induces a secondcurrent in the secondary windings that in turn produces a correspondingsecond voltage across load 260. The amount and polarity of the secondcurrent and voltage are determined, at least in part, by the amount andpolarity of the first current, which is in turn determined by the shapedvoltage and operation of one of current switches 297 a-b. Thus, whenpresented with a shaped voltage and a transmission control signal, poweramplifier 290 converts the shaped voltage into a shaped transmissionsignal corresponding to both the digital shaping control signal and thetransmission control signal provided by co-controller 222.

FIG. 2C illustrates various signals of sonar transmitter 230 inaccordance with an embodiment of the disclosure. Graphs 200C, 201C, and202C show simulations of unshaped transmission signal 282 c, analogshape control signal 285 c, and shaped transmission signal 218 c,respectively, where shaped transmission signal 218 c has been formedusing a slow changing envelope (e.g., analog shape control signal 285 c)relative to the transmission control signal (e.g., corresponding tounshaped transmission signal 282 c).

In some embodiments, transmitter 230 may be used to excite atransmission channel of multichannel sonar transducer 250, asillustrated in FIG. 2A, and/or may be used to implement a portion oftransceiver 234 to excite transducer 264. In other embodiments,transmitter 230 may be used to excite a single sonar, radar, or othertype sensor element and/or load, for example, or multiple sensorelements and/or sensor channels. In general, embodiments of transmitter230 may be used with any type of sensor system that utilizestransmission signals to operate and that would benefit from shapedtransmission signals, as described herein. For example, load 260 may beimplemented as a sonar transducer, a radar antenna, a transducer and/orantenna array, and/or other loads adapted to accept an electricaltransmission signal and produce corresponding sound and/or other typesof propagating mechanical and/or electromagnetic pulses or waves.

FIGS. 3A-B illustrate diagrams of multichannel sonar systems inaccordance with embodiments of the disclosure. In the embodimentillustrated in FIG. 3A, multichannel sonar system 300 includestransducer assembly 210 with multichannel transducer 250 coupled toadditional components (e.g., user interface 120) though cable 214. Asshown, in some embodiments, multichannel transducer 250 may beimplemented with multiple longitudinally adjacent linear transducerelements 351 coupled to integral electronics 320 (e.g., transmitters,receivers, transceivers, controllers, and/or other electronics) throughconductive ribbons 318 a-b. Each transducer element 351 may, in someembodiments, be implemented from a piezoelectric material and/or formedfrom one or more electrically coupled piezoelectric bars. Conductiveribbon 318 a may be implemented with multiple conductive traces (e.g.,one per channel), for example, and conductive ribbon 318 b may beimplemented with a single relatively wide conductive plane that may forma ground plane/current return and help to shield linear transducerelements 351 from external electromagnetic interference. In someembodiments, conductive ribbon 318 a may be adapted to shield lineartransducer elements 351 from electromagnetic interference from externalsources and from integral electronics 320, such as by using relativelywide conductive traces to substantially cover the opposing face ofmultichannel transducer 250, for example, and/or by including a separateground plane trace in addition to the multiple conductive traces coupledto the channels of multichannel transducer 250.

In typical embodiments, the number of transducer elements 351 equals thenumber of channels of multichannel transducer 250. However, in otherembodiments, multiple transducer elements 351 may be electricallycoupled to form a single channel. For example, in one embodiment, pairsof adjacent transducer elements may be electrically coupled to form areduced number of channels in order to reduce electronics complexity andcost, form differently shaped acoustic beams and/or return patterns,and/or conform to other produce design specifications. In someembodiments, conductive ribbons 318 a-b may be configured toelectrically couple multiple transducer elements 351 into a reducednumber of channels. In other embodiments, integral electronics 320(e.g., co-controller 222) may be configured to operate multiple physicalchannels as a single channel and produce a similar result but withoutrequiring physical changes to integral electronics 320, conductiveribbons 318 a-b, and/or multichannel transducer 250.

As shown in FIG. 3A, multichannel transducer 250 may be disposed withinhousing 211 between an optional acoustic matching layer 353 adjacent anacoustic face 212 of transducer assembly 210 and an acoustic backinglayer 352. In embodiments including acoustic matching layer 353,acoustic matching layer 353 may be configured (e.g., through selectionof shape, thickness, and/or material, including variations in each) toallow multichannel transducer 250 (and transducer assembly 210) to beoperated at a much wider frequency band (e.g., transmit and/or receiveband) than conventional sonar systems. For example, acoustic matchinglayer 353 may be formed from a metal or metal oxide filled epoxy (e.g.,alumina, stainless steel, copper, and/or other metal and/or metal oxidepowder, flakes, microballs, and/or other type of filler). In someembodiments, a thickness of acoustic matching layer 353 may roughlycorrespond to a quarter-wavelength of the excitation signal (e.g., of acentral frequency of the excitation signal) used to generate acousticbeams using multichannel transducer 250.

Acoustic backing layer 352 may be configured to provide structuralsupport for multichannel transducer 250, to help mechanically isolatemultichannel transducer 250 from other components of transducer assembly210, and/or to help shield multichannel transducer 250 fromelectromagnetic interference. In some embodiments, acoustic backinglayer 352 may be formed from a relatively rigid substrate (e.g.,fiberglass, other laminates, metal sheet, and/or other rigid substrates)substantially encapsulated in a relatively resilient material (e.g.,rubber, foam, and/or other acoustic baffling materials).

As noted in FIG. 3A, in some embodiments, housing 211 may includewaterproof layer 311 a and/or mount bracket 311 b. In some embodiments,waterproof layer 311 a may be formed from a polyurethane plastic and/orother types of thermosetting polymers substantially transparent toacoustic signals and able to be overmoulded into and/or around housing211 and/or multichannel transducer 250. For example, waterproof layer311 a may form acoustic face 212 of transducer assembly 210, forexample, and be sealed to remaining portions of housing 211 to formhousing 211. In general, housing 211 may be configured to providestructural and/or protective support for transducer assembly 210. Insome embodiments, at least some portions of housing 211 may beimplemented from a machined, cast, and/or injection moulded material,such as a metal, ceramic, and/or plastic (e.g., a polycarbonate,polyurethane, and/or other plastic) material that can be formed into oneor more rigid, pliable, and/or combination of rigid and pliablestructures. Mount bracket 311 b may be formed from the same or differentmaterials, for example, and may be configured to physically coupletransducer assembly 210 to a mobile structure (e.g., transom 107 b ofmobile structure 101 in FIG. 1B). In some embodiments, mount bracket 311b, housing 211, and/or transducer assembly 210 may be implemented withone or more actuators to adjust an orientation and/or position oftransducer assembly 210, as described herein.

In the embodiment illustrated in FIG. 3B, multichannel sonar system 301includes transducer assembly 210 implemented with multichanneltransducer 250 and optional transducer 364. As shown, in someembodiments, multichannel transducer 250 may be implemented withphysically differentiated transmission channel 360 and receiver channels362, so as to differentiate the shapes of the corresponding acousticbeams and acoustic returns, as described herein. In the illustratedembodiment, transmission channel 360 may extend centrally through andbeyond receiver channels 362 into an end of housing 211, therebyproducing an acoustic beam that is narrower that the acoustic returnsfor receiver channels 362. Although the beamwidths of receiver channels362 are wider, the effective system beamwidth would be equal to thenarrower beam (e.g., the acoustic beam produced by transmission channel360). Transmission channel 360 may be formed from one relatively longtransducer element, for example, or from multiple relatively shortelectrically coupled transducer elements in order to reducedifferentiated manufacturing costs and/or to reduce a risk of thermalwarping and/or related damage.

Also shown in FIG. 3B, transducer assembly 210 may be implemented withoptional transducer 364. In various embodiments, transducer 364 may beconfigured to produce acoustic beams with shapes, orientations, and/orfrequencies different from those produced by multichannel transducer250. For example, transducer 364 may be implemented with a circulartransducer element configured to produce relatively narrow conicalacoustic beams, for example, to facilitate depth measurements in deepwater. In other embodiments, transducer 364 may be configured to produceacoustic beams configured to compliment operation of multichanneltransducer 250.

FIGS. 3C-D illustrate diagrams 300C and 300D of various transducerconfigurations for multichannel sonar systems in accordance withembodiments of the disclosure. For example, configuration 301C in FIG.3C includes a single substantially square multichannel transducer 250with similarly sized linear transmission and receiver channels.Configuration 302C includes a single substantially rectangularmultichannel transducer 250 and a circular transducer 264 laterallyaligned with a center linear channel of multichannel transducer 250.Configuration 303C includes a single multichannel transducer 250 with anelongated transmission channel 260 relative to receiver channels 262.Configuration 304C includes a single multichannel transducer 250 with anelongated transmission channel 260 relative to receiver channels 262,and a circular transducer 264 offset from both transmission channel 260and receiver channels 262. Diagrams 300D of FIG. 3D provide embodimentsof multichannel transducer configurations adapted to provide additionalwidth of coverage. For example, configuration 301D includes a singlemultichannel transducer 250 with similarly sized linear and transmissionchannels, but arranged in a curved array rather than a plane array.Configuration 302D includes two spatially differentiated planar arrays250 a-b, where planar arrays 250 a-b are oriented differently and areadjacent and/or adjoining along one edge. In some embodiments, planararrays 250 a-b may form a single multichannel transducer, for example,or may form multiple multichannel transducers.

As described herein, each of these configurations may be implementedwith integral electronics and within a single housing of a correspondingtransducer assembly. In some embodiments, multiple such embodiments maybe formed within a single housing, for example, and/or may be coupledtogether to form a more complex multichannel sonar system.

FIG. 3E illustrates various sonar beams produced by multichannel sonarsystems (e.g., multichannel transducer 250) in accordance withembodiments of the disclosure. In each of graphs 300E, 301E, and 302E,position 250 e indicates a spatial location of a center channel ofmultichannel transducer 250 relative to the corresponding graphelements, with constituent linear elements longitudinally aligned toextend perpendicularly into and/or out of the page. For example, graph300E shows transmission beam 360 e and return beams 362 e correspondingto transmission channel 260 and receive channels 262 of multichanneltransducer 250, similar to the arrangement shown in FIG. 3A, with atotal of 32 channels and processed to form 27 return beams, as describedherein.

As shown in graph 300E, transmission beam 360 e is a fan-shaped beamextending laterally with respect to an orientation of transmissionchannel 260. Each of return beams 362 e are sonar return beams formedradially between maximum operating angles within transmission beam 360 eby beamforming and/or interferometry processing applied to acousticreturns received by one or more receive channels 262 of multichanneltransducer 250. For example, pairs of acoustic returns fromcorresponding pairs of adjacent receive channels 262 may be processed(e.g., by co-controller 222) to form corresponding return beams for eachpair, where each return beam may be characterized by an orientation,shape, and/or one or more beam widths. In some embodiments, three ormore receive channels may be used to form each return beam. In variousembodiments, return beams 362 e (as shown in graph 300E) indicate thespatial equivalents of the programmatically formed beams, andco-controller 222 may be configured to form return beams 362 e to benarrower and/or oriented differently from the acoustic returnscorresponding to a receive channel acting alone (e.g., which wouldtypically have relatively wide fan-shaped patterns similar in dimension,shape, and orientation to transmission beam 360 e). As shown, in someembodiments, such beamforming and/or interferometry processing can beconfigured to produce relatively narrow multiple return beams 362 with arange of orientations, which can be used to generate higher resolutionand higher quality sonar imagery relative to conventional sonar systems,as described herein.

Graph 301E includes a single sonar return beam 362 e, which may beformed by processing acoustic returns received by two or more receivechannels 262 of multichannel transducer 250, for example. Graph 310Eillustrates the effective spatial sensitivity of return beam 362 erelative to a position and orientation of multichannel transducer 250.Graph 302E includes inter-beam angle conversion basis 363 e, which maybe used to determine accurate signal amplitudes and correspondingrelative angles for signal detail received by return beam 362 e shown ingraph 301E and one or more other return beams 362 shown in graph 300E.For example, a signal detail may include a signal spike associated withan object in a water column, and that signal spike may be recognizablein acoustic returns provided by multiple receive channels, but be offsetin time due to different signal path lengths. After the acoustic returnsare converted into sonar return beams, inter-beam angle conversion basis363 e may be used to resolve the position of the object from the signalspikes as reproduced in return beams 362 e. With one or more suchinter-beam conversion bases, acoustic returns received by multiplechannels and/or return beams can be more accurately localized to aspecific orientation and/or position relative to multichannel transducer250.

FIG. 4A illustrates a cross section 400 of a transducer assembly 410(e.g., similar to transducer assembly 210 of FIG. 3A) in accordance withan embodiment of the disclosure. In the embodiment shown in FIG. 4A,transducer assembly 410 includes multichannel transducer 450 configuredto emit acoustic beams and receive acoustic returns through surface 412of housing 411. Integral electronics 420 are configured to controloperation of transducer assembly 410 and are electrically coupled tomultichannel transducer 450 through traces 418 a and foil 418 b, whichmay be routed, at least in part, through or around acoustic backinglayer 452, and through cavities 426, spacers 424, and/or substrate 422.Substrate 422 may be configured to provide structural support for and/orelectrical coupling between various elements of integral electronics420, for example, and, in some embodiments, may be configured to providethermal sinking for integral electronics 420 to and/or through housing411. Spacers 424 may be configured to provide structural support forvarious elements of transducer assembly 410, including substrate 422,integral electronics 420, and/or multichannel transducer 450 forexample, and may be configured to help provide mechanical isolation ofintegral electronics 420 from multichannel transducer 450. In someembodiments, cavities 426 may be filled with a material configured toenhance thermal sinking of integral electronics 420, to increasemechanical isolation of integral electronics 420, and/or to minimizethermal stress within housing 411 caused by thermal cycling oftransducer assembly 410, for example.

As shown, multichannel transducer 450 may include multiple transducerelements 451 substantially electrically and/or mechanically isolatedfrom each other and/or a side of housing 411 by spacers 452. In someembodiments, one or more of spacers 452 may be implemented substantiallyas cavities. Each transducer element 451 may be individually and/orcollectively electrically coupled (e.g., soldered, clamped, conductivelyglued, and/or otherwise electrically coupled) to traces 418 a and foil418 b and thereby to integral electronics 420. In some embodiments,multichannel transducer 450 may include acoustic matching layer 453disposed adjacent to emission surface 412, which may be configured tobroaden an operational bandwidth of multichannel transducer 450.

In some embodiments, transducer assembly 410 may include additionaltransducers and/or more than one multichannel transducer, for example,and may be arranged differently from the arrangement shown in FIG. 4A.In various embodiments, multichannel transducer 450 may include adifferent number of transducer elements 451 than shown in FIG. 4A. Eachof transducer elements 451 may be implemented as one or moresubstantially linear and/or conical transducer elements, for example,and be made of a ceramic material, a metal or alloy material, apiezoelectric material, a combination of insulating and conductivematerials, and/or other single or multi-layered transducing materialsthat can be energized by an electrical signal to produce an acousticbeam and/or that can produce electrical signals in response to acousticreturns (e.g., received through emission surface 412).

In one embodiment, one or more of transducer elements 451 may beimplemented from polarized polyvinylidene difluoride (PVDF) and/or otherthermoplastic polymers. In such embodiment, all transducer elements 451may be manufactured from a single sheet of the material by formingelectrodes into the required shapes and patterns for each transducerelement. Such shapes can be rectangular, circular, and/or otherpatterns, and/or can be formed into shapes or patterns designed toreduce side lobe levels. Once formed, the shaped electrodes may be cutfrom the sheet and assembled to form transducer elements 451, traces 418a, and/or foil 418 b of multichannel transducer 450, for example, or theentire sheet may be used to form transducer elements 451, traces 418 a,foil 418 b, and/or spacers 452, where spacers 452 may be implemented byportions of the material without electrodes.

FIGS. 4B-4C illustrate diagrams 400B and 400C of various transducerelements and their corresponding acoustic beams in accordance withembodiments of the disclosure. FIG. 4B shows linear transducer element410 b producing a fan shaped acoustic beam 448 b from emission surface412 b having footprint 450 b, where linear transducer element 410 b andemission surface 412 b may correspond to transducer element 451 andemission surface 412 of transducer assembly 410. The overall dimensionsand shape of fan shaped acoustic beam 448 b roughly correspond to theradiation pattern produced by linear transducer element 410 b asreferenced to half power (−3 dB) beamwidth limits of the pattern, as isknown in the art. For example, longitudinal length 440 b (L1) oftransducer element 410 b may be roughly related to the lateral beamwidth446 b (B1) by: B1 ˜50*λ/L1, and lateral length 444 b (L2) of transducerelement 410 b may be roughly related to the longitudinal beamwidth 442 b(B2) by: B2 ˜50*λ/L2, where λ is the wavelength of the signal used toexcite transducer element 410 b. Also shown are center axis 452 b andorthogonal axes 454 b and 456 b, which may be used as references todefine an orientation and/or aiming angles of transducer element 410 band/or footprint 450 b, such as a depression/emission angle and/or aroll, pitch, and/or yaw of transducer element 410 b and/or acoustic beam448 b. Acoustic returns received by transducer element 410 b exhibit aspatial pattern similar to that of the acoustic beam shown in FIG. 4B.

FIG. 4C shows circular transducer element 410C producing a conicalacoustic beam 448 c from emission surface 412 c having footprint 450 c,where circular transducer element 410 c and emission surface 412 c maycorrespond to transducer element 451 (e.g., and/or transducer 363 ofFIG. 3B) and emission surface 412 of transducer assembly 410. Theoverall dimensions and shape of conical acoustic beam 448 c roughlycorrespond to the radiation pattern produced by circular transducerelement 410 c as referenced to half power (−3 dB) beamwidth limits ofthe pattern, as is known in the art. For example, diameter 440 c (D1) oftransducer element 410 c may be roughly related to the beamwidth 442 c(B1) by: B1 ˜65*k/D1, where λ is the wavelength of the signal used toenergize transducer element 410 c. Also shown is center axis 452 c,which may be used as a reference to define an orientation and/oraiming/emission angle of transducer element 410 c and/or footprint 450c, such as a depression angle and/or a roll and/or pitch of transducerelement 410 c and/or acoustic beam 448 c.

In some embodiments, linear transducer element 410 b and/or circulartransducer element 410 c may be implemented as a transducer elementassembly, for example, including multiple individual transducer elementscoupled together electrically and/or physically to act as a singletransducer element. For instance, in one embodiment, linear transducerelement 410 b may be implemented as multiple rectangular, circular,and/or otherwise shaped elements soldered together and arranged in ashape roughly corresponding to the shape of linear transducer element410 b, so as to collectively produce fan shaped acoustic beam 448 b. Inanother embodiment, circular transducer element 410 c may be implementedas multiple circular, rectangular, and/or otherwise shaped elementssoldered together and arranged in an overall shape roughly correspondingto the circular shape of circular transducer element 410 c, so as tocollectively produce conical acoustic beam 448 c. In such embodiments,interstitial spaces between elements may be filled with a material tohelp secure the elements to each other and form a transducer elementassembly. In one embodiment, the interstitial material may be similarthe material used for acoustic matching layer 453.

In various embodiments, the orientation and/or aiming angles, thelongitudinal beamwidth 442 b, lateral beamwidth 446 b, and/or beamwidth442 c may be selected (e.g., by adjusting the orientation and/or angles,by selecting a shape and/or size of linear transducer element 410 band/or circular transducer 410 c, and/or by adjusting the excitationwavelength) to emphasize detail (e.g., narrower acoustic beams and/orsmaller excitation wavelengths) in a particular direction, to emphasizebreadth of coverage (e.g., broader acoustic beams and/or largerexcitation wavelengths) in a particular direction, and/or to emphasizepenetration distance (e.g., narrower acoustic beams and/or largerexcitation wavelengths), for example, among other sonar systemcharacteristics. Embodiments of the present disclosure provide theability to adjust such characteristics according to the localenvironment (e.g., shallow water, deep sea, approach to a shallowsubmerged object, tracking of a deep school of fish), according to anoperational state of a coupled mobile structure (e.g., narrow, forwardlooking, and quickly updated depth measurements while at speed, broadside and down looking and/or target searching while at rest searchingfor fish), and/or according to other orientation, position, and/oroperational characteristics of a coupled mobile structure.

FIGS. 5-7 illustrate various display views of sonar data provided by amultichannel sonar system in accordance with embodiments of thedisclosure. For example, display view 500 of FIG. 5 illustrates aninstantaneous side view of a water column and bed ensonified bymultichannel transducer 250 and/or transducer assembly 210. As shown,display view 500 includes imagery depicting bed 510, sunken boat 512,tire 514, and school of fish 520, combined with a graphic 550 indicatingan outline of a transmission beam/return beam area for multichanneltransducer 250. Importantly, display view 500 illustrates howembodiments of multichannel transducer 250 may be used to produce sonardata and/or imagery instantaneously indicating water column and bedcharacteristics that are differentiated both by their depth and theirrelative port or starboard position without a central missing trough.Additionally, display view 500 illustrates how embodiments ofmultichannel transducer 250 may be used to produce sonar imagery ofrelatively broad areas instantaneously and be detailed enough to detecttire 514 and/or school of fish 520 (e.g., relatively small objects).

In some embodiments, embodiments of the disclosed 3D capablemultichannel sonar system (e.g., system 100B of FIG. 1B and/ortransducer assembly 210 of FIG. 2A) may be configured to detect anorientation and/or position of mobile structure 101 and/or multichanneltransducer 250 and adjust an orientation and/or position of multichanneltransducer 250 and/or adjust processing of acoustic returns received bymultichannel transducer 250 to substantially align the orientationsand/or positions of multiple instantaneous views with each other and/orwith a vertical down direction. For example, transducer assembly 210 maybe configured to apply a translational and/or rotational coordinateframe transformation to sonar data and/or imagery to align multipleinstantaneous views.

Display view 501 of FIG. 5 illustrates an aggregate side view of a watercolumn and bed ensonified by multichannel transducer 250 and/ortransducer assembly 210. As shown, display view 501 includes imagerydepicting bed 510, sunken boat 512, and school of fish 520, includingsampled and un-sampled time series 552 and 554. In some embodiments,display view 501 may be formed from multiple instances of display view500 rotated 90 degrees about a vertical axis, and may include similardetail and breadth enhancements. For example, port and/or starboardimage detail occupying the same position in a rotated display view 501may be overlaid, blended, and/or otherwise combined in display view 501.In other embodiments, transducer assembly 210 may be configured to formdisplay view 501 by using transmission channel 260 to produce a timeseries of acoustic beams and only a subset of receive channels 262(e.g., between one and five channels) to receive a corresponding timeseries of acoustic returns, and then processing the acoustic returns toproduce sampled time series 552, similar to operation of a conventionalsingle channel transducer. In some embodiments, transducer assembly 210may be configured to substantially align the orientations and/orpositions of each sample within sampled time series 552 through physicaladjustments and/or processing.

Display view 502 of FIG. 5 illustrates port and starboard differentiatedaggregate side views of a water column and bed ensonified bymultichannel transducer 250 and/or transducer assembly 210. As shown,display view 502 includes port and starboard sampled time series 552 a-bdepicting port and starboard perspectives of bed 510 a and 510 b andsunken boat 512 a and 512 b, and port view of tire 514 and starboardview of school of fish 520. In some embodiments, display view 502 may beformed from multiple instances of display view 500 differentiated intoport and starboard portions and rotated 90 degrees about a verticalaxis. In other embodiments, transducer assembly 210 may be configured toform display view 502 by using transmission channel 260 to produce atime series of acoustic beams and port and starboard subsets of receivechannels 262 to receive corresponding time series of port and starboardacoustic returns, and then processing the port and starboard acousticreturns to produce port and starboard sampled time series 552 a-b. Insome embodiments, transducer assembly 210 may be configured tosubstantially align the orientations and/or positions of each samplewithin port and starboard sampled time series 552 a-b.

In related embodiments, transducer assembly 210 may be configured toadjust an effective depression angle and/or range of angles defining theport and starboard perspectives using beamforming and/or interferometryprocessing, as described herein. For example, display view 502 may becharacterized as port and starboard differentiated down perspectives. Insome embodiments, transducer assembly 210 may be configured to adjustthe effective depression angle and/or range of angles according to ameasured depth of the water column, a speed of mobile structure 101,and/or other operational states of transducer assembly 210 and/or mobilestructure 101.

Display view 503 of FIG. 5 illustrates port and starboard differentiatedaggregate side views of a water column and bed ensonified bymultichannel transducer 250 and/or transducer assembly 210, similar tobut oriented differently from display view 502. In addition, displayview 503 illustration an embodiment where transducer assembly 210 isconfigured to adjust the effective depression angle and/or range ofangles defining the port and starboard perspectives such that displayview 503 may be characterized as port and starboard differentiated sideperspectives (e.g., similar to conventional sidescan sonar).

As shown, display view 503 includes depicts port and starboardperspectives of bed 510 a and 510 b and sunken boat 512 a and 512 b, andport view of tire 514 and starboard view of school of fish 520. In someembodiments, display view 503 may be formed from multiple instances ofdisplay view 500 differentiated into port and starboard portions androtated to produce display view 503. In other embodiments, transducerassembly 210 may be configured to form display view 503 by usingtransmission channel 260 to produce a time series of acoustic beams andport and starboard subsets of receive channels 262 to receivecorresponding time series of port and starboard acoustic returns, andthen processing the port and starboard acoustic returns to producedisplay view 503. In some embodiments, transducer assembly 210 may beconfigured to substantially align the orientations and/or positions ofeach sample derived from the port and starboard acoustic returns to formdisplay view 503.

Display view 504 of FIG. 5 illustrates an aggregate vertical down viewof a water column and bed ensonified by multichannel transducer 250and/or transducer assembly 210. As shown, display view 504 includesimagery depicting bed 510, sunken boat 512, and tire 514. In someembodiments, display view 504 may be formed from multiple instances ofdisplay view 500 rotated 90 degrees about a horizontal axis. Forexample, different depth image detail occupying the same position in arotated display view 504 may be overlaid, blended, and/or otherwisecombined in display view 504. In other embodiments, transducer assembly210 may be configured to form display view 504 by using transmissionchannel 260 to produce a time series of acoustic beams and receivechannels 262 to receive a corresponding time series of acoustic returns,and then processing the acoustic returns to produce display view 504. Insome embodiments, transducer assembly 210 may be configured to processthe acoustic returns using inter-beam interpolation processing, forexample, in addition to and/or alternatively to processing the acousticreturns using beamforming and/or interferometry processing. In someembodiments, transducer assembly 210 may be configured to substantiallyalign the orientations of each sample derived from the acoustic returnsto form display view 504 through physical adjustments and/or processing.Such processing may be used generally to improve image accuracy and/oraspect ratio, and therein overall image quality.

Display view 600 of FIG. 6 illustrates a three dimensional adjustableperspective view of a water column and bed ensonified by multichanneltransducer 250 and/or transducer assembly 210. As shown, display view600 includes imagery depicting bed 510, sunken boat 512, tire 514, andschool of fish 520. In some embodiments, display view 600 may be formedfrom multiple instances of display view 500 arranged in a volumetricrendering and adjustably rotated to produce display view 600. Forexample, overlapping image detail in display view 600 may be overlaid,blended, and/or otherwise combined in display view 600. In otherembodiments, transducer assembly 210 may be configured to form displayview 600 by using transmission channel 260 to produce a time series ofacoustic beams and receive channels 262 to receive a corresponding timeseries of acoustic returns, and then processing the acoustic returns toproduce display view 600. In some embodiments, transducer assembly 210may be configured to process the acoustic returns using inter-beaminterpolation processing, for example, in addition to and/oralternatively to processing the acoustic returns using beamformingand/or interferometry processing. In some embodiments, transducerassembly 210 may be configured to substantially align the orientationsof each sample derived from the acoustic returns to form display view600 through physical adjustments and/or processing. Such processing maybe used generally to improve image accuracy and/or aspect ratio, andtherein overall image quality.

Display view 601 of FIG. 6 illustrates a three dimensional adjustableperspective view of a water column and bed ensonified by multichanneltransducer 250 and/or transducer assembly 210. As shown, display view601 includes imagery depicting bed 510, sunken boat 512, tire 514, andschool of fish 520, combined with graphic 550 indicating an outline of atransmission beam/return beam area for multichannel transducer 250,graphic 630 indicating a relative position and/or orientation of mobilestructure 101, graphic 632 indicating waypoint information, and graphic634 indicating an absolute and/or relative position of the waypoint. Invarious embodiments, display view 601 may be formed using the same orsimilar techniques as described with respect to display view 600. Inaddition, transducer assembly 210 may be configured to receive userinput (e.g., provided to user interface 120) selecting a position,depth, and/or other characteristics for the waypoint. In someembodiments, transducer assembly 210 may be configured to estimate arange-to-cast from mobile structure 101 to position 634 and use graphic632 to display the range-to-cast to a user. Such estimate may be based,at least in part, on an absolute and/or relative position of mobilestructure 101, a speed of mobile structure 101, and/or other operationalstates of mobile structure 101. In various embodiments, a range-to-castestimation may include multiple orthogonal distance estimations, forexample, and/or a relative or absolute heading and radius estimation.

Display view 602 of FIG. 6 illustrates a three dimensional adjustablebathymetric view of portions of a water channel or bed ensonified bymultichannel transducer 250 and/or transducer assembly 210. As shown,display view 602 includes chart 640 and graphics 644 configured toindicate variable depth along the sonar sweeps 642. In variousembodiments, display view 602 may be formed by rendering chart 640,which may include various land features in addition to an outline of abody of water, and rendering point cloud graphics 644 corresponding toacoustic returns received by multichannel transducer 250 as it is movedacross sonar sweeps 642. In some embodiments, graphics 644 may beconfigured to indicate variable depths through differentiated colors,transparency, and/or other types of differentiated graphicscharacteristics. Portions of a body of water not ensonified bymultichannel transducer 250 and/or transducer assembly 210 may be leftblank, for example, or may be assigned a color or other graphicscharacteristic configured to indicate a lack of bathymetric sonar data.

Display views 700 and 701 of FIG. 7 illustrate aggregate side views of awater column and bed ensonified by multichannel transducer 250 and/ortransducer assembly 210, similar to display view 501 of FIG. 5. Asshown, display views 700 and 701 include imagery depicting bed 510, net516, and school of fish 520. In various embodiments, display view 700may be formed using the same or similar techniques as described withrespect to display view 501. In such embodiments, portion 750 of displayview 700 may include overlaid, blended, or otherwise combined image datathat partially or completely obscures port or starboard image detailthat lie at the same depth. In some embodiments, transducer assembly 210may be configured to provide additional image detail by forming displayview 701, in which port and starboard data are differentiatedgraphically, such as through use of differentiated colors (e.g., red forport-side sonar data and green for starboard-side sonar data), as shownin portion 752 of display view 701.

In various embodiments, each of the display views illustrated in FIGS.5-7 may be formed using the same transducer assembly 210 and/ormultichannel transducer 250, for example, and/or approximately the sameset of data processed differently by transducer assembly 210 accordingto user input, configuration parameters, and/or other operational statesof transducer assembly 210. This contrasts with conventional sonartransducers which would typically require multiple individual transducersystems, relatively expensive and large transducer assemblies, andmultiple processing systems to produce a similar set of perspectives butwithout the image quality made possible by embodiments of the presentdisclosure. Additionally, transducer assembly 210 may be configured torender and/or display (e.g. using user interface 120) multiple differentdisplay views side by side, for example, and display characteristicsand/or arrangements in each of the display views depicted in FIGS. 5-7may be used in any combination or sub-combination to form differentdisplay views with one or more of the described display characteristicsand/or arrangements.

FIGS. 8-9 illustrate various configurations of multichannel sonarsystems in accordance with embodiments of the disclosure. For example,diagram 800 shows ship 810, transducer assembly 850 (e.g., an embodimentof transducer assembly 210 including multichannel transducer 250), andacoustic beam 852 before and after rotation of transducer assembly 850from a first downward fixed position to a second starboard fixedposition. In some embodiments, transducer assembly 850 may beimplemented with a bracket (e.g., transom bracket 311 b) and/oractuators configured to provide adjustment of an orientation oftransducer assembly 850, which may be used to rotate transducer assembly850 about a longitudinal axis to extend ensonification to port orstarboard, as shown. For example, one embodiment of transducer assembly850 may be implemented with a 120 degree beamwidth that limits theextent of its ensonifications to approximately twice the depth to eitherside of ship 810. By rotating transducer assembly 850, transducerassembly 850 can be used with a bias to port or starboard in order toprovide improved sidescan imagery in a corresponding direction. Invarious embodiments, transducer assembly 850 may be configured tomeasure an orientation and/or position of transducer assembly 850 whileoperating, for example, and then use such sensor information to aligncorresponding samples with each other and/or with a down direction, asdescribed herein.

Diagram 801 shows ship 810, transducer assembly 850 coupled to pole 811,and acoustic beam 852 used to ensonify portions of a water column and/orbed under dock 820. In some embodiments, transducer assembly 850 may bephysically coupled to a pole or other type of manual or actuated probeconfigured to insert transducer assembly 850 into areas where ship 810cannot easily reach, such as under dock 820 and/or within a submergedtree. Embodiments of the present disclosure make this possibly byproviding a relatively compact transducer assembly and/or multichanneltransducer. In various embodiments, transducer assembly 850 may beconfigured to measure an orientation and/or position of transducerassembly 850 while operating, for example, and then use such sensorinformation to align corresponding samples with each other and/or with adown or other relative or absolute direction to form various displayviews, including three dimensional display views, as described herein.In one embodiment, transducer assembly 850 may be configured to comparesamples and/or images to each other and align the samples/images basedon one or more common structures detected in the samples/images.

Diagram 802 shows ship 810, transducer assembly 850 coupled to a frontof ship 810, and acoustic beams 852 a (e.g., a longitudinally alignedacoustic beam) and 852 b (a laterally aligned acoustic beam) that may beused to ensonify portions of a water column and/or bed under or near afront of ship 810. In some embodiments, transducer assembly 850 may beadjustably coupled to a hull of ship 810 near its bow so as to aid innavigation. In various embodiments, transducer assembly 850 may beconfigured to measure an orientation and/or position of transducerassembly 850 while operating, for example, and then use such sensorinformation to align corresponding samples with each other and/or with adown or other relative or absolute direction to form various displayviews, including three dimensional display views, as described herein.In one embodiment, transducer assembly 850 may be configured to receivea speed of ship 810 and adjust (e.g., using one or more actuators) adepression angle and/or an acoustic beam orientation of transducerassembly 850 (e.g., from acoustic beam 852 a to 852 b) to providefurther forward imagery as the speed is increased.

Diagram 803 shows ship 810, transducer assembly 850 a coupled to atransom of ship 810, transducer assembly 850 b coupled to a starboardside of ship 810, and corresponding laterally aligned acoustic beam 852a and longitudinally aligned acoustic beam 852 b. In some embodiments,transducer assembly 850 a may be implemented with a bracket (e.g.,transom bracket 311 b), hinge, and/or actuators configured to provideadjustment of an orientation and/or position of transducer assembly 850a, which may be used to rotate transducer assembly 850 a about a lateralaxis to sweep acoustic beam 852 a from the stern surface of the water tothe bed, for example, and provide a substantially three dimensionalstern view, among other display views described herein. Similarly,transducer assembly 850 b may be implemented with a bracket, hinge,and/or actuators that may be used to rotate transducer assembly 850 babout a longitudinal axis to sweep acoustic beam 852 b from thestarboard surface of the water to the bed, for example, and provide athree dimensional starboard view. In various embodiments, transducerassemblies 850 a-b may be configured to measure their orientationsand/or positions while operating and then use such sensor information toalign corresponding samples with each other and/or with a down or otherrelative or absolute direction to form various high quality and aligneddisplay views, including three dimensional display views, as describedherein.

Diagram 804 shows transducer assembly 850 coupled to rotating pole 811and corresponding acoustic beams 852. In some embodiments, transducerassembly 850 may be physically coupled to a pole or other type of manualor actuated probe configured to rotate transducer assembly 850 about aprobe axis. In addition, transducer assembly 850 may be implemented witha bracket (e.g., transom bracket 311 b), hinge, and/or actuatorsconfigured to provide adjustment of an orientation and/or position oftransducer assembly 850 relative to an end of pole 811. Pole 811 may beused to rotate transducer assembly 850 about a corresponding probe axisto provide radar-like, periodically updated two and/or three dimensionalviews, for example, among other display views described herein. Invarious embodiments, transducer assembly 850 may be configured tomeasure an orientation and/or position of transducer assembly 850 whileoperating, for example, and then use such sensor information to aligncorresponding samples with each other and/or with a down or otherrelative or absolute direction to form various display views, includingthree dimensional display views, as described herein.

Diagram 805 shows port and starboard transducer assemblies 850 a and 850b coupled to ship 810 and oriented to produce respective port andstarboard acoustic beams 852 a and 85 sb. In some embodiments,transducer assemblies 850 a and 850 b may be oriented to ensonify alarger arc of water column and bed than a single transducer assembly,for example, and/or to provide display views with finer image detailthan offered by a single transducer assembly. A 3D capable multichannelsonar system including two or more transducer assemblies (e.g.,transducer assemblies 850 a and 850 b) may be configured to timeensonifications of each assembly in a coordinated fashion, for example,to synchronize ensonifications (e.g., to reduce a risk of electricalinterference) and/or to stagger or otherwise pattern (e.g., spatiallyand/or temporally)) ensonifications to reduce a risk of acousticinterference. Such timing may be implemented over an interface supportedby cable 214 and/or controllers 220 and/or 222, for example. In oneembodiment, such timing may be implemented according to the IEEE 1588Precision Timing Protocol. In various embodiments, transducer assemblies850 a and 850 b may be configured to measure their orientations and/orpositions while operating, for example, and then use such sensorinformation to align corresponding samples with each other and/or with adown or other relative or absolute direction to form various displayviews, including three dimensional display views, as described herein.

FIG. 9 illustrates various configurations of a limited (e.g., with twochannels) multichannel embodiment of transducer assembly 210 andmultichannel transducer 250. Such embodiments would not produce sonarimagery with as much of the detail provided by embodiments withadditional channels, but such embodiments could be configured to providerough angular information that is not available with conventional singlechannel sonar systems. For example, conventional single channel sonarsystems produce sonar imagery that is a combination of acoustic returnsfrom all sides of the ship/transducer, meaning a user would not know onwhich side an imaged target of interest lies. A transducer assemblyimplemented with a two channel multichannel transducer may be configuredto use interferometry and/or time of arrival processing to discriminatetargets closer to one channel than another, for example, and in someembodiments provide a user with an indication of the true range to thetarget from the ship. Such systems could be implemented inexpensively,as compared to alternative systems with many more channels, for example,and need not be configured to perform certain processing steps, such asbeamforming processing.

For example, diagram 900 of FIG. 9 shows transducer assembly 950 (e.g.,implemented with a two channel multichannel transducer) coupled to ship810, target 920, acoustic beam 952, and differentiated return paths 954.As shown, return paths 954 from target 920 to transducer assembly 950are slightly different for the two channels of transducer assembly 950,and transducer assembly 950 may be configured to detect that differenceand determine a corresponding side (e.g. starboard) for samplesincluding acoustic returns from target 920. In some embodiments,transducer assembly 950 may be configured to use one or both channels ascombined transmission and receive channels, as described herein. Inother embodiments, transducer assembly 950 may additionally include aseparate transmission channel. In further embodiments, a transducerassembly implemented with a many channel multichannel transducer may beconfigured to operate with only two channels, similar to transducerassembly 950. In various embodiments, transducer assembly 950 may beconfigured to measure its orientation and/or position and then use suchsensor information to align corresponding samples with each other and/orwith a down or other relative or absolute direction to form variousdisplay views, including three dimensional display views, as describedherein.

Diagram 901 shows multiple transducer assemblies 950 a and 950 b (e.g.,both implemented with a two channel multichannel transducer) coupled toship 810, and corresponding acoustic beams 952 a and 952 b. Diagram 902shows transducer assemblies 950, 950 a, and 950 b of diagrams 900 and901 coupled to ship 810, and corresponding acoustic beams 950, 952 a,and 952 b. Diagrams 901 and 902 illustrate how multiple two channeltransducer assemblies can be combined with a single mobile structure toprovide port and starboard, or port, starboard, and down ensonificationsand thereby increase the coverage of the associated water column and/orbed. In various embodiments, transducer assemblies 950, 950 a, and/or950 b may be configured to measure their orientations and/or positionsand then use such sensor information to align corresponding samples witheach other and/or with a down or other relative or absolute direction toform various display views, including three dimensional display views,as described herein.

FIGS. 10A-B illustrate flow diagrams of respective processes 1000A and1000B to provide sonar data and/or imagery for mobile structure 101 inaccordance with embodiments of the disclosure. In some embodiments, theoperations of FIGS. 10A-B may be implemented as software instructionsexecuted by one or more logic devices associated with correspondingelectronic devices, sensors, and/or structures depicted in FIGS. 1Athrough 4C. More generally, the operations of FIGS. 10A-B may beimplemented with any combination of software instructions and/orelectronic hardware (e.g., inductors, capacitors, amplifiers, actuators,or other analog and/or digital components).

It should be appreciated that any step, sub-step, sub-process, or blockof processes 1000A and 1000B may be performed in an order or arrangementdifferent from the embodiments illustrated by respective FIGS. 10A-B.For example, in other embodiments, one or more blocks may be omittedfrom the various processes, and blocks from one process may be includedin another process. Furthermore, block inputs, block outputs, varioussensor signals, sensor information, calibration parameters, and/or otheroperational parameters may be stored to one or more memories prior tomoving to a following portion of a corresponding process. Althoughprocesses 1000A and 1000B are described with reference to systems 100,100B, 200, 201, 300, 301, and/or 400 and FIGS. 1A-4C, processes 1000Aand 1000B may be performed by other systems different from those systemsand including a different selection of electronic devices, sensors,assemblies, mobile structures, and/or mobile structure attributes.

Process 1000A represents a method for providing sonar data and/orimagery for mobile structure 101 using systems 100, 100B, 200, 201, 300,301, and/or 400 in accordance with embodiments of the disclosure. At theinitiation of process 1000A, various system parameters may be populatedby prior execution of a process similar to process 1000A, for example,or may be initialized to zero and/or one or more values corresponding totypical, stored, and/or learned values derived from past operation ofprocess 1000A, as described herein.

In block 1002, a logic device transmits a sonar signal. For example,controller 220 and/or co-controller 222 of transducer assembly 210 maybe configured to control transmitter 230 to provide a shaped or unshapedtransmission signal to transmission channel 260 of multichanneltransducer 250 and produce a corresponding acoustic beam. In someembodiments, controller 220 and/or co-controller 222 may be configuredto control transceiver 234 to provide a shaped or unshaped transmissionsignal to transducer 264 and produce a corresponding acoustic beam. Invarious embodiments, transducer assembly 210 may be configured to usetemperature sensor 266 and/or orientation/position sensor 240 to recordcorresponding measurements at substantially the same time. Notificationof transmission and/or other sensor information may be relayed to otherdevices of system 100 through cable 214.

In block 1004, a logic device receives acoustic returns from amultichannel transducer. For example, controller 220 and/orco-controller 222 may be configured to control one or more of receivers232 to receive acoustic returns from one or more of receive channels 262of multichannel transducer 250, for example, and provide the receivedacoustic returns (e.g., in digital form) to co-controller 222. In otherembodiments, controller 220 and/or co-controller 222 may be configuredto control transceiver 234 to receive acoustic returns from transducer264 and provide the received acoustic returns (e.g., in digital form) toco-controller 222. In some embodiments, receivers 232 and/or transceiver234 may be configured to convey the acoustic returns to co-controller222 over a baseband channel. In other embodiments, receivers 232,transceiver 234, and/or co-controller 222 may be configured to decimatethe acoustic returns before performing further processing. In variousembodiments, transducer assembly 210 may be configured to usetemperature sensor 266 and/or orientation/position sensor 240 to recordcorresponding measurements at substantially the same time. Notificationof reception and/or other sensor information may be relayed to otherdevices of system 100 through cable 214.

In block 1006, a logic device forms one or more sonar return beams fromthe acoustic returns. For example, controller 220 and/or co-controller222 may be configured to perform beamforming, interferometry, and/orinter-beam interpolation processing on the acoustic returns received inblock 1004 to form the one or more sonar return beams. In someembodiments, such processing may be performed on acoustic returnsgrouped from two, three, or more receive channels, for example,depending on the desired number of beams, the desired range of beamorientations, and/or other system configuration parameters. In variousembodiments, controller 220 and/or co-controller 222 may be configuredto determine an inter-beam angle conversion basis for each sonar returnbeam, which may be used to determine accurate return beam signalamplitudes as a function of the angle for each sonar return beam, asdescribed herein. In some embodiments, controller 220 and/orco-controller 222 may be configured to decimate, scale, filter, and/orotherwise process or post-process the sonar return beams before storingthe amplitudes, inter-beam angles, and/or other characteristics of thesonar return beams (e.g., for each sample) and proceeding to block 1008.Notification of processing and/or other sensor information may berelayed to other devices of system 100 through cable 214.

In block 1008, a logic device generates sonar image data from the sonarreturn beams. For example, controller 220 and/or co-controller 222 maybe configured to process the individual sonar return beams (e.g.,according to their corresponding orientation angles and/or signalamplitudes) into depth (e.g., time from transmission to reception),position (e.g., orientation angle for the sonar return beam), and/orintensity (e.g., signal amplitude) sonar data, for each sample.Controller 220 and/or co-controller 222 may be configured to convertsuch sonar data and/or samples into two dimensional and/or threedimensional sonar imagery and/or display views, as described herein. Insome embodiments, controller 220 and/or co-controller 222 may beconfigured to use corresponding recorded temperature, orientation,and/or position measurements to align acoustic returns, samples, sonardata, and/or imagery with each other and/or one or more directions, suchas down. Sonar data, imagery, display views, and/or other sensorinformation may be relayed to other devices of system 100 (e.g., userinterface 120) through cable 214. In some embodiments, transducerassembly 210 may be configured to display sonar data, imagery, displayviews, and/or other sensor information to a user through use of userinterface 120, for example, such as receiving user selection of adesired display view and then relaying corresponding sonar data and/orimagery to user interface 120.

It is contemplated that any one or combination of methods to providesonar data and/or imagery may be performed according to one or moreoperating contexts of a control loop, for example, such as a startup,learning, running, and/or other type operating context. For example,process 1000A may proceed back to block 1002 and proceed through process1000A again to produce updated sonar data and/or imagery, as in acontrol loop.

Process 1000B represents a method for providing sonar data and/orimagery for mobile structure 101 using systems 100, 100B, 200, 201, 300,301, and/or 400 in accordance with embodiments of the disclosure. At theinitiation of process 1000B, various system parameters may be populatedby prior execution of a process similar to process 1000B, for example,or may be initialized to zero and/or one or more values corresponding totypical, stored, and/or learned values derived from past operation ofprocess 1000B, as described herein.

In block 1010, a logic device receives sonar image data from amultichannel sonar system. For example, controller 220 of transducerassembly 210 may be configured to receive sonar image data generated byco-controller 222 in communication with multichannel transducer 250,similar to the process described in block 1008 of process 1000A. Invarious embodiments, controller 220 may be configured to receive anorientation and/or position of transducer assembly 210 with the sonarimage data.

In block 1012, a logic device receives an updated orientation and/orposition of a multichannel transducer system. For example controller 220may be configured to receive an absolute and/or relative orientation(e.g., roll, pitch, and/or yaw) and/or position from anorientation/position sensor integrated with transducer assembly 210(e.g., orientation/position sensor 240), bracket 311 b, and/or assemblybracket/actuator 116. In various embodiments, the measured transducerorientation may be derived from one or more absolute and/or relativeorientation measurements made by orientation sensors, actuators, steppermotors, and/or other devices coupled to mobile structure 101. In someembodiments, the updated measurements may be received substantiallysynchronously with processing of block 1014.

In block 1014, a logic device receives updated sonar image data from amultichannel sonar system. For example controller 220 may be configuredto receive updated sonar image data generated by co-controller 222 incommunication with multichannel transducer 250 at a subsequent timerelative to processing of block 1010. In various embodiments, theupdated sonar image data may be generated using a process similar toprocess 1000A.

In block 1016, a logic device combines sonar image data and updatedsonar image data based on an updated orientation and/or position. Forexample controller 220 may be configured to combine the sonar image datareceived in block 1010 with the updated sonar image data received inblock 1014 based on the updated orientation and/or position measurementsreceived in block 1012. In various embodiments, controller 220 may beconfigured to user the sensor measurements to align the sonar image datawith the updated sonar image data and/or align both to a particulardirection (e.g., down) accurately, as described herein. In someembodiments, controller 220 may be configured to align the sonar imagedata using common image detail. Resulting imagery may be two dimensionaland/or three dimensional, as described herein.

In block 1018, a logic device displays the combined sonar image data.For example, controller 220 may be configured to relay the combinedimage data to user interface 120 to display the combined image data to auser of mobile structure 101. In some embodiments, controller 220 may beconfigured to render one or multiple different display views of thecombined image data, for example, and relay the display views and/orcorresponding sonar image data to user interface 120.

It is contemplated that any one or combination of methods to providesonar data and/or imagery may be performed according to one or moreoperating contexts of a control loop, for example, such as a startup,learning, running, and/or other type operating context. For example,process 1000B may proceed back to block 1010 and proceed through process1000B again to produce updated sonar data and/or imagery, as in acontrol loop.

Embodiments of the present disclosure can thus provide inexpensive,feature-filled, reliable, compact, and accurate sonar systems, dataand/or imagery. Such embodiments may be used to provide sonar data toassist in navigation and/or mapping for a mobile structure and/or toassist in the operation of other systems, devices, and/or sensorscoupled to the mobile structure.

When generating reconstructions of a 3D underwater scene using sonarsystems, there are often competing requirements for the sonar data. Forexample, it may be better to use a lower frequency to detect theunderwater bottom surface, while a higher frequency may provide betterdetection of objects protruding from the bottom. Therefore, for anenhanced rendering of the bottom surface in an underwater scene, it canbe advantageous to use different sources of sonar data, each of whichmay be selected to be better suited for the task of generating and/orrendering the bottom surface and/or other aspects of the underwaterscene.

Embodiments described herein enhance the rendering of the bottom surfaceby using one source of sonar data for the generation of the surfacestructures and other sonar data and/or other data sources to enhance therendering of the surface. Examples of the data sources are sidescansonar systems/subsystems, a ranging system or geographical map orunderwater camera or combinations of such sensors and/or data sources.

For example, such sonar systems may be configured to take sonar data andcorresponding position data and optionally attitude data to generate a3D representation of an underwater scene; create a 2D rectangular gridthat overlays the 3D scene with fixed coordinates in the horizontalplane, but with adjustable coordinates in the vertical plane; separatethe echo returns associated with the bottom features and those thatcorrespond to targets in the water; working with the echo returns fromthe bottom features, apply sonar data to the grid such that each echoreturn contributes to the closest vertex of the grid and the closestpixel in the texture; convert the grid to a 3D surface by generatingtriangles for cells in the grid that have vertices with contributingecho returns; plot the surface in a 3D underwater scene; generate ahigh-resolution texture, from sources of data such as a sidescan sonarsystem or subsystem, a ranging system, a geographical map, an underwatercamera, or combinations of such data sources; register such textureswith the 3D surface and stretch over the triangles; repeat for new sonardata but update only the triangles that have changed or been added;and/or extend this technique to multiple grids so that a continuoustrack can be represented, and/or any combination of these.

More specifically, embodiments may take sonar data and position data andoptionally attitude data to generate a 3D representation of anunderwater scene in a point cloud format; separate the echo returnsassociated with the bottom features and those that correspond to targetsin the water; define a grid in the XY plane (e.g., longitudinal/lateralplane) with a fixed resolution in meters (e.g., the cell size) that isdefined by the currently selected range, which has a fixed extent ingrid cells either side of the first ensonification center; aggregate newdata for echo returns associated with the bottom to provide the depths(e.g., Z/vertical coordinates for the grid vertices); and subdividecells with defined depths by triangles generated to represent thesurface of the bottom and structures attached to the bottom. In someembodiments, another source of data may be provided, such as sidescansonar data from a sidescan sonar subsystem, or a ranging system orgeographical map or underwater camera or combinations of these, and thesystem may be configured to generate a texture or textures that extendsover the grid, such that the texture stores the intensities and/ordepths at a higher resolution than the grid and thus provides a higherresolution image of the bottom structure. Such texture(s) can also beused to show visual data, such as visual data acquired from anunderwater camera. In various embodiments, the texture may be registeredwith the grid (e.g., using knowledge of the orientation of the sensorsand sonar system elements) and aligned over the 3D representation XYgrid, and the resulting 3D sonar data may be rendered on a display to auser such that the user may re-orientate the scene using a graphicalinterface provided by the display (e.g., an elements of user interface120).

FIGS. 11A-B illustrate diagrams 1100 and 1102 of various transducerconfigurations for multichannel sonar systems (e.g., 3D capablemultichannel sonar systems providing enhanced sonar imagery) inaccordance with embodiments of the disclosure. In particular,configurations 1100 and 1102 use interferometric sonar subsystems of amultichannel sonar system to generate 3D models or representations of anunderwater scene and enhance such 3D models with additional sonar dataprovided by sidescan sonar subsystems integrated within the samemultichannel sonar system.

More generally, a sonar system combining desirable aspects of twodifferent sonar subsystems may include a transmitter channel and atleast a pair of receiver channels operating around a first frequency,where the transmitter channel may be a separate channel or combined withthe receiver channels. Such sonar system may include a secondtransmitter channel and at least a receiver channel operating around asecond frequency, where the transmitter channel may be a separatechannel or combined with the receiver channel, as described herein. Thesystem may be configured to transmit at the first frequency and receiveon the plurality of associated receiver channels and process to producea section of a 3D representation of the underwater environment. Suchsonar data may be combined with optional position data and optionalattitude data to enhance the 3D sonar data. The system may be configuredto transmit at the second frequency, either at the same time as thefirst frequency or after the first frequency to avoid interference, toreceive at the second frequency on the associated receiver channel, toand generate a 2D sidescan texture.

In various embodiments, the system may conduct a series of multipletransmissions and acquisitions and combine the resulting set of spatialsonar data to generate a continuous 3D representation of the environmentthat has been interrogated and an associated 2D sidescan texture. Forexample, the system may generate a 3D representation of the underwaterbottom surface using the data from the first frequency and render withthe 2D texture generated from the second frequency, and/or generate a 3Drepresentation of in-water targets and render with the data obtainedfrom the second frequency. In some embodiments, the two sonar subsystemsmay be implemented within the same housing. In general, the varioustransducer elements may be relatively long and thin to produce narrowbeams fore-aft and wide beams port-starboard, as described herein.

For example, configuration 1100 in FIG. 11A includes two sets oftransducer elements, namely an interferometric sonar system transmittertransducer 1160 and corresponding interferometric sonar system receivertransducers 1162-1 and 1162-2 (e.g., a three channel multichannel sonarsubsystem), and a sidescan sonar system transmitter transducer 1170 andcorresponding sidescan sonar system receiver transducer 1172 (e.g., atwo channel multichannel sonar subsystem). Configuration 1102 in FIG.11A also includes two sets of transducer elements, but in a more compactconfiguration, namely an interferometric sonar systemtransmitter/receiver or transceiver transducer 1164 and correspondinginterferometric sonar system receiver transducer 1162-2 (e.g., a twochannel multichannel sonar subsystem), and a sidescan sonar systemtransmitter/receiver or transceiver transducer 1174 (e.g., a singlechannel sonar subsystem). Each configuration shown in FIGS. 11A-B arecross sectional views from an end of transducer housing 211, showing thestarboard side of the sonar system and the top of housing 211 generallyparallel to the water surface. As shown in FIGS. 11A-B, the 3D orinterferometric sonar subsystem can produce both 3D spatial sonar dataand 2D sidescan sonar data (e.g., another type of spatial sonar data),while the sidescan sonar subsystem can only produce sidescan sonar data.

In general, interferometric sonar systems/subsystems employ at least tworeceiver channels to perform interferometry on sonar returns sensed byeach individual receiver channel to provide directionality and range toa source of a sonar return/reflection. Sidescan sonar systems/subsystemstypically employ a single receiver channel. In some embodiments, eachindividual receiver channel/transducer element may be implemented by alinear transducer element longitudinally aligned with a longitudinalaxis of mobile structure 101, so as to sense sonar returns within a fanshaped beam oriented generally orthogonally to the longitudinal axis(e.g., a direction of travel) of mobile structure 101. In theembodiments shown in FIGS. 11A-B, a pair of each configuration may bemounted to port and starboard sides of hull 105 b to generate port andstarboard sonar imagery, as described herein. In other embodiments, apair of each configuration may be joined to each other to formtransducer assembly 112, for example. In other embodiments, transducerassembly 112 may be configured to provide only port or starboard sonarimagery.

FIGS. 12A-B illustrate various display views 1200 and 1202 of sonar dataprovided by embodiments of multichannel sonar system configurations 1100and/or 1102, in accordance with embodiments of the disclosure. Forexample, display view 1200 of FIG. 12A illustrates port and starboardsidescan sonar images of a water column and bed ensonified bycorresponding port and starboard embodiments of interferometric sonarsystem transmitter transducer 1160 and corresponding interferometricsonar system receiver transducers 1162-1 and 1162-2, for example, or byinterferometric sonar system transmitter/receiver or transceivertransducer 1164 and corresponding interferometric sonar system receivertransducer 1162-2. Display view 1202 of FIG. 12B illustrates port andstarboard sidescan sonar images of the same water column and bedensonified by corresponding port and starboard embodiments of sidescansonar system transmitter transducer 1170 and corresponding sidescansonar system receiver transducer 1172, for example, or by sidescan sonarsystem transmitter/receiver or transceiver transducer 1174.

Importantly, display views 1200 and 1202 illustrate how embodiments ofmultichannel transducer configurations 1100 and 1102 may be used toproduce sonar data and/or imagery indicating water column and bedcharacteristics that are differentiated both by their depth and theirrelative port or starboard position, for example, and the configurationsof their respective multichannel sonar subsystems. For instance, it isapparent from FIG. 12A that multichannel interferometric sonar systemconfigurations can be configured to provide more spatial detail but lessresolution and/or contrast than sidescan sonar system configurationsoperated at higher frequencies. Sonar data from both types of sonarsystem configurations may be registered to each other and combined toform 3D sonar data and/or imagery with desirable aspects of each type orsource of sonar data.

As noted herein, the quality and clarity of a sidescan image (e.g., asshown in display views 1200 and 1202) can be improved by using higherfrequencies, but higher frequencies do not travel as far in the water aslower frequencies, so the range of the generated image can be limited.In embodiments with two or more collocated sidescan sonars that operateat different frequencies, sonar imagery can be produced that combinesthe best qualities from each of the contributing sonar subsystems. Forexample, a sidescan image could be constructed where the high frequencysonar data is used for short ranges, while lower frequency sonar datacan be used for longer ranges. Therefore, an enhanced image can beproduced that has higher detail at shorter ranges and data out to longerranges, which would not be available for the higher frequency alone.Embodiments provide enhanced sidescan sonar imagery by combining sourcesof data from collocated sonar subsystems, such as those shown in FIGS.11A-B. Such sonar subsystems may be operated to avoid interference,either by differentiating their frequencies sufficiently or byinterleaving ensonifications. Embodiments of such dual frequency sonarsystems can be implemented by physically separate sonar systems andmounted in an approximate collocation on a vessel or tow fish or may becombined in a single housing such that the transducers are collocated,as shown in FIGS. 11A-B.

Methods for avoiding interference may include interleavingtransmissions/ensonifications such that the sequence is time divisionmultiplexed (TDM) between the subsystems; synchronizing transmissionssuch that transmissions start at the same time on all systems;synchronizing transmissions such that transmissions are staggered butalmost simultaneous (e.g., starting a second ensonification just as thefirst ensonification ends, and ending the second ensonification beforedesirable sonar returns from the first ensonification begin to bereceived).

Methods for combining the frequency differentiated sonar data mayinclude preprocessing to adjust the individual sources sonar data fornoise reduction and optimized intensity and/or sensitivity. Then thefrequency differentiated sonar data may be combined using one or acombination of the following non-exclusive list of techniques: linearweighted addition of sonar data; non-linear weighted combination ofsonar data; weighted combination with inspection to select maximum afterweighting.

FIG. 13A-C illustrate various display views 1300, 1302, and 1304 ofsonar data provided by a multichannel sonar system in accordance withembodiments of the disclosure. The sonar system used to generate displayviews 1300, 1302, and 1304 included a single set of electronicsconnected to a transducer assembly containing both a low frequencysidescan set of transducers (e.g., an interferometric sonar subsystem)and a set of high frequency sidescan transducers (e.g., a sidescan sonarsubsystem), similar to configurations 1100 and 1102 of FIGS. 11A-B. Theraw sonar data from each subsystem was acquired using TDM techniques toavoid interference. The combined result (e.g., shown in FIG. 13C) wasobtained using a non-linear addition of sonar data from each subsystemafter preprocessing for noise and intensity.

The non-linear algorithm was achieved through inspection of the highfrequency data (e.g., FIG. 13B), which exhibits a non-linear degradationof intensity with range. The algorithm was therefore chosen to have asimilar non-linear relationship with range. The actual algorithm usedwas as follows:

The combined sonar data (e.g., result) at a particular range cell for aparticular transmission and sidescan side=A*high frequency sonar data atthe corresponding range cell +(1−A)*low frequency sonar data at thecorresponding range cell, where

A=(Range/Maximum Range){circumflex over ( )}0.75

This technique results in the data at zero range equaling the highfrequency data, the data at maximum range equaling the low frequencydata and the data in between equaling a non-linear combination of thetwo sources of data.

FIGS. 13A-C illustrate the source low and high frequency sonar data andthe combined sonar data results. The low frequency sonar data (e.g.,display view 1300 of FIG. 13A) extends out to the maximum display range,while the high frequency sonar data (e.g., display view 1302 of FIG.13B) falls below the system noise level before the maximum displayrange. It can be seen that the high frequency sonar data has morecontrast and more detail than the low frequency sonar data, but lacksthe range of the low frequency sonar data. The combined sonar dataimagery (e.g., display view 1304 of FIG. 13C) both extends out to themaximum display/system range and also shows higher detail than the lowfrequency sonar data imagery does alone.

FIG. 14A illustrates a flow diagram of process 1400 to provide sonardata and/or imagery for mobile structure 101 in accordance withembodiments of the disclosure. In some embodiments, the operations ofFIG. 14 may be implemented as software instructions executed by one ormore logic devices associated with corresponding electronic devices,sensors, structures, display views, and/or processes depicted in FIGS.1A through 13C. More generally, the operations of FIG. 14 may beimplemented with any combination of software instructions and/orelectronic hardware (e.g., inductors, capacitors, amplifiers, actuators,or other analog and/or digital components).

It should be appreciated that any step, sub-step, sub-process, or blockof process 1400 may be performed in an order or arrangement differentfrom the embodiments illustrated by FIG. 14. For example, in otherembodiments, one or more blocks may be omitted from the variousprocesses, and blocks from one process may be included in anotherprocess. Furthermore, block inputs, block outputs, various sensorsignals, sensor information, calibration parameters, and/or otheroperational parameters may be stored to one or more memories prior tomoving to a following portion of a corresponding process. Althoughprocess 1400 is described with reference to systems 100, 100B, 200, 201,300, 301, and/or 400 and FIGS. 1A-4C, process 1400 may be performed byother systems different from those systems and including a differentselection of electronic devices, sensors, assemblies, mobile structures,and/or mobile structure attributes. Process 1400 represents a method forproviding sonar data and/or imagery for mobile structure 101 usingsystems 100, 100B, 200, 201, 300, 301, 400, and/or other systems,subsystems, transducer arrangements, and/or configurations in accordancewith embodiments of the disclosure. At the initiation of process 1400,various system parameters may be populated by prior execution of aprocess similar to process 1400, for example, or may be initialized tozero and/or one or more values corresponding to typical, stored, and/orlearned values derived from past operation of process 1400, as describedherein.

In block 1402, a logic device receives a series of acoustic returns froma multichannel transducer. For example, controller 220 and/orco-controller 222 may be configured to control one or more of receivers232 to receive acoustic returns from one or more of receive channels 262of multichannel transducer 250, for example, and provide the receivedacoustic returns (e.g., in digital form) to co-controller 222. In otherembodiments, controller 220 and/or co-controller 222 may be configuredto control one or more of receivers 232 to receive acoustic returns frominterferometric sonar subsystem receiver channels 1162-1 and 1162-2. Infurther embodiments, controller 220 and/or co-controller 222 may beconfigured to control transceiver 234 to receive a second series ofacoustic returns from sidescan sonar subsystem receiver channel 1172 andprovide the second set of received acoustic returns (e.g., in digitalform) to co-controller 222. In various embodiments, transducer assembly210 may be configured to use temperature sensor 266 and/ororientation/position sensor 240 to record corresponding measurements atsubstantially the same time. Notification of reception and/or othersensor information may be relayed to other devices of system 100 throughcable 214. Controller 220 and/or co-controller 222 may be configured toaggregate a series of such acoustic returns and/or other data to form atime series of acoustic returns, for example.

In block 1404, a logic device generates a set of spatial sonar databased on a series of acoustic returns. For example, controller 220and/or co-controller 222 may be configured to generate a set of spatialsonar data (e.g., as shown in display views 1200, 1202, 1300, and 1302)based, at least in part, on the series of acoustic returns received inblock 1402. In some embodiments, where the series of acoustic returnsare provided by an interferometric sonar subsystem of the multichanneltransducer, such set of spatial sonar data may include range and/ordirectional data associated with each one of the series of acousticreturns received in block 1404, for example, and/or a first set ofsidescan sonar data based on the same set of acoustic returns. Inembodiments where a second series of acoustic returns are provided by asidescan sonar subsystem of the multichannel transducer, a second set ofspatial sonar data may be generated, such as a set of sidescan sonardata, as described herein.

In block 1406, a logic device generates a 3D representation of anunderwater environment based on a set of spatial sonar data. Forexample, controller 220 and/or co-controller 222 may be configured togenerate a 3D representation of an underwater environment based, atleast in part, on the set of spatial sonar data generated in block 1404,as described herein. For example, such 3D representation may include a3D grid of depths of a bottom of the underwater environment, such as abathymetric grid of the underwater environment.

In block 1408, a logic device generates an enhanced 3D representationbased on a 3D representation and a set of spatial data. For example,controller 220 and/or co-controller 222 may be configured to generate anenhanced 3D representation of the underwater environment based, at leastin part, on the 3D representation generated in block 1406 and a set ofspatial data different from the set of spatial sonar data generated inblock 1404. Such differentiated spatial data may include sidescan sonardata from the same interferometric sonar subsystem (e.g., by processingthe acoustic returns differently to generate sidescan sonar data), sonardata from a different sonar system or subsystem, a camera, a rangingsystem, a chart, and/or other spatial data sources, as described herein.In embodiments where the multichannel transducer includes aninterferometric sonar subsystem and a sidescan sonar subsystem, thedifferentiated set of spatial data may include a second set of spatialsonar data, such as a set of sidescan sonar data generated by the firstseries of acoustic returns (from the interferometric sonar subsystem)and/or a second series of acoustic returns received in block 1402 (fromthe sidescan sonar subsystem).

In alternative embodiments, controller 220 and/or co-controller 222 maybe configured to generate an enhanced sidescan representation of theunderwater environment based, at least in part, on first and second setsof sidescan sonar data generated in block 1404, as described herein. Forexample, controller 220 and/or co-controller 222 may be configured tocombine a first set of sidescan sonar data provided by aninterferometric sonar subsystem of the multichannel transducer with asecond set of sidescan sonar data provided by a sidescan sonar subsystemof the multichannel transducer. In some embodiments, controller 220and/or co-controller 222 may be configured to generate the enhanced 3Drepresentation of the underwater environment based, at least in part, ona combination of the 3D representation (e.g., derived from the acousticreturns provided by the interferometric sonar subsystem), a set ofsidescan sonar data (e.g., derived from the acoustic returns provided bythe sidescan sonar subsystem), and a set of interferometric sidescansonar data (e.g., derived from the acoustic returns provided by theinterferometric sonar subsystem).

Once the enhanced 3D representation and/or enhanced sidescanrepresentation is generated, controller 220 and/or controller 130 may beconfigured to relay the enhanced 3D and/or sidescan representations touser interface 120 to display the enhanced 3D and/or sidescanrepresentations to a user of mobile structure 101. In some embodiments,controller 220 may be configured to render one or multiple differentdisplay views of the enhanced 3D and/or sidescan representations, forexample, and relay the display views and/or corresponding sonar imagedata to user interface 120.

It is contemplated that any one or combination of methods to providesonar data and/or imagery may be performed according to one or moreoperating contexts of a control loop, for example, such as a startup,learning, running, and/or other type operating context. For example,process 1400 may proceed back to block 1402 and proceed through process1400 again to produce updated sonar data and/or imagery, as in a controlloop. In addition, it is also contemplated that such methods to providesonar data and/or imagery may be performed substantially in real timeand/or generally synchronous with acquisition of acoustic returns, so asto provide a user of mobile structure with substantially real timeawareness of the underwater environment associated with navigation ofmobile structure 101.

Embodiments of the present disclosure can thus provide inexpensive,feature-filled, reliable, compact, and accurate sonar systems, dataand/or imagery. Such embodiments may be used to provide sonar data toassist in navigation and/or mapping for a mobile structure and/or toassist in the operation of other systems, devices, and/or sensorscoupled to the mobile structure.

Where applicable, various embodiments provided by the present disclosurecan be implemented using hardware, software, or combinations of hardwareand software. Also where applicable, the various hardware componentsand/or software components set forth herein can be combined intocomposite components comprising software, hardware, and/or both withoutdeparting from the spirit of the present disclosure. Where applicable,the various hardware components and/or software components set forthherein can be separated into sub-components comprising software,hardware, or both without departing from the spirit of the presentdisclosure. In addition, where applicable, it is contemplated thatsoftware components can be implemented as hardware components, andvice-versa.

Software in accordance with the present disclosure, such asnon-transitory instructions, program code, and/or data, can be stored onone or more non-transitory machine readable mediums. It is alsocontemplated that software identified herein can be implemented usingone or more general purpose or specific purpose computers and/orcomputer systems, networked and/or otherwise. Where applicable, theordering of various steps described herein can be changed, combined intocomposite steps, and/or separated into sub-steps to provide featuresdescribed herein.

Embodiments described above illustrate but do not limit the invention.It should also be understood that numerous modifications and variationsare possible in accordance with the principles of the invention.Accordingly, the scope of the invention is defined only by the followingclaims.

What is claimed is:
 1. A system comprising: a sonar transducer assemblyincluding a housing adapted to be mounted to a mobile structure; amultichannel transducer disposed within the housing; and a logic deviceconfigured to communicate with the multichannel transducer, wherein thelogic device is configured to: receive a series of acoustic returns fromthe multichannel transducer; generate a set of spatial sonar data based,at least in part, on the series of acoustic returns; and generate anenhanced three dimensional (3D) and/or sidescan representation of anunderwater environment associated with the mobile structure based, atleast in part, on a set of spatial data different from the set ofspatial sonar data.
 2. The system of claim 1, wherein the logic deviceis configured to: generate a 3D representation of the underwaterenvironment based, at least in part, on the set of spatial sonar data;and generate the enhanced 3D representation of the underwaterenvironment based, at least in part, on a combination of the 3Drepresentation of the underwater environment the set of spatial datadifferent from the set of spatial sonar data.
 3. The system of claim 2,wherein: the set of spatial data different from the set of spatial sonardata comprises a differentiated set of spatial sonar data, image dataprovided by a camera, ranging system data, and/or chart data.
 4. Thesystem of claim 1, wherein the series of acoustic returns comprises afirst series of acoustic returns, the set of spatial sonar datacomprises a first set of sidescan sonar data, and the multichanneltransducer comprises: an interferometric sonar subsystem disposed withinthe housing and configured to provide the first series of acousticreturns; and a sidescan sonar subsystem disposed within the housing andconfigured to provide a second series of acoustic returns, wherein thelogic device is configured to: receive the second series of acousticreturns; generate a second set of sidescan sonar data based, at least inpart, on the second series of acoustic returns; and generate theenhanced sidescan representation of the underwater environment based, atleast in part, on a combination of the first and second sets of sidescansonar data.
 5. The system of claim 4, wherein: the interferometric sonarsubsystem is configured to operate at a first frequency or across afirst band of frequencies; and the sidescan sonar subsystem isconfigured to operate at a second frequency higher than the firstfrequency or across a second band of frequencies higher than the firstband of frequencies.
 6. The system of claim 1, wherein the series ofacoustic returns comprises a first series of acoustic returns, andwherein the multichannel transducer comprises: an interferometric sonarsubsystem configured to provide the first series of acoustic returns;wherein the logic device is configured to: receive a second series ofacoustic returns from a sidescan sonar subsystem mounted to the mobilestructure; generate a set of sidescan sonar data based, at least inpart, on the second series of acoustic returns; generate a 3Drepresentation of the underwater environment based, at least in part, onthe set of spatial sonar data; and generate the enhanced 3Drepresentation of the underwater environment based, at least in part, ona combination of the 3D representation and the set of sidescan sonardata.
 7. The system of claim 6, wherein the logic device is configuredto: generate a set of interferometric sidescan sonar data based, atleast in part, on the first series of acoustic returns; and generate theenhanced 3D representation of the underwater environment based, at leastin part, on a combination of the 3D representation, the set of sidescansonar data, and the set of interferometric sidescan sonar data.
 8. Thesystem of claim 1, further comprising a temperature sensor, anorientation sensor, and/or a position sensor, wherein the logic deviceis configured to: receive temperature, orientation, and/or positionmeasurements from the temperature, orientation, and/or position sensors;and generate the set of spatial sonar data based, at least in part, onthe temperature, orientation, and/or position measurements.
 9. Thesystem of claim 8, wherein: the mobile structure comprises a watercraft;the logic device, temperature sensor, orientation sensor, and/orposition sensor are disposed within the housing; and the transducerassembly is adjustably mounted to a transom of the watercraft, a hull ofthe watercraft, a side of the watercraft, and/or an actuated and/ormanual probe coupled to the watercraft and/or held by a user of thewatercraft.
 10. The system of claim 1, further comprising a userinterface configured to display the enhanced 3D and/or sidescanrepresentation of the underwater environment to a user, wherein thelogic device is adapted to: generate one or more selected display viewsfrom the enhanced 3D and/or sidescan representation of the underwaterenvironment; and display the one or more selected display views to theuser, wherein the selected display views comprise an instantaneous view,an aggregate side view, a port and starboard differentiated aggregateside view, a port and starboard perspective view, an aggregate verticaldown view, a three dimensional perspective view, a three dimensionalbathymetric view, and/or a graphically differentiated port and starboarddifferentiated aggregate side view.
 11. A method comprising: receiving aseries of acoustic returns from a multichannel transducer disposedwithin a housing of a sonar transducer assembly adapted to be mounted toa mobile structure; generating a set of spatial sonar data based, atleast in part, on the series of acoustic returns; and generating anenhanced three dimensional (3D) and/or sidescan representation of anunderwater environment associated with the mobile structure based, atleast in part, on a set of spatial data different from the set ofspatial sonar data.
 12. The method of claim 11, further comprising:generating a 3D representation of the underwater environment based, atleast in part, on the set of spatial sonar data; and generating theenhanced 3D representation of the underwater environment based, at leastin part, on a combination of the 3D representation of the underwaterenvironment the set of spatial data different from the set of spatialsonar data.
 13. The method of claim 12, wherein: the set of spatial datadifferent from the set of spatial sonar data comprises a differentiatedset of spatial sonar data, image data provided by a camera, rangingsystem data, and/or chart data.
 14. The method of claim 11, wherein theseries of acoustic returns comprises a first series of acoustic returns,the set of spatial sonar data comprises a first set of sidescan sonardata, and the multichannel transducer comprises: an interferometricsonar subsystem disposed within the housing and configured to providethe first series of acoustic returns; and a sidescan sonar subsystemdisposed within the housing and configured to provide a second series ofacoustic returns, wherein the logic device is configured to: receive thesecond series of acoustic returns; generate a second set of sidescansonar data based, at least in part, on the second series of acousticreturns; and generate the enhanced sidescan representation of theunderwater environment based, at least in part, on a combination of thefirst and second sets of sidescan sonar data.
 15. The method of claim14, wherein: the interferometric sonar subsystem is configured tooperate at a first frequency or across a first band of frequencies; andthe sidescan sonar subsystem is configured to operate at a secondfrequency higher than the first frequency or across a second band offrequencies higher than the first band of frequencies.
 16. The method ofclaim 11, wherein the series of acoustic returns comprises a firstseries of acoustic returns, and wherein the multichannel transducercomprises: an interferometric sonar subsystem configured to provide thefirst series of acoustic returns; wherein the logic device is configuredto: receive a second series of acoustic returns from a sidescan sonarsubsystem mounted to the mobile structure; generate a set of sidescansonar data based, at least in part, on the second series of acousticreturns; generate a 3D representation of the underwater environmentbased, at least in part, on the set of spatial sonar data; and generatethe enhanced 3D representation of the underwater environment based, atleast in part, on a combination of the 3D representation and the set ofsidescan sonar data.
 17. The method of claim 16, further comprising:generating a set of interferometric sidescan sonar data based, at leastin part, on the first series of acoustic returns; and generating theenhanced 3D representation of the underwater environment based, at leastin part, on a combination of the 3D representation, the set of sidescansonar data, and the set of interferometric sidescan sonar data.
 18. Themethod of claim 11, further comprising: receiving temperature,orientation, and/or position measurements from temperature, orientation,and/or position sensors; and generating the set of spatial sonar databased, at least in part, on the temperature, orientation, and/orposition measurements.
 19. The method of claim 18, wherein: the mobilestructure comprises a watercraft; the temperature sensor, orientationsensor, and/or position sensor are disposed within the housing; and thetransducer assembly is adjustably mounted to a transom of thewatercraft, a hull of the watercraft, a side of the watercraft, and/oran actuated and/or manual probe coupled to the watercraft and/or held bya user of the watercraft.
 20. The method of claim 11, furthercomprising: generating one or more selected display views from theenhanced 3D and/or sidescan representation of the underwaterenvironment; and displaying the one or more selected display views tothe user, wherein the selected display views comprise an instantaneousview, an aggregate side view, a port and starboard differentiatedaggregate side view, a port and starboard perspective view, an aggregatevertical down view, a three dimensional perspective view, a threedimensional bathymetric view, and/or a graphically differentiated portand starboard differentiated aggregate side view.